In any other era this story would have been seen as as controversial as The Deadly Assassin (which revealed more about the Doctor's background than ever before, and also, by placing him tangibly among his own kind, portrayed him for the first time as vulnerable, out of his depth and thus more mortal) was in its day, in its radical take on the nature of the Doctor and the Timelord makeup. But in a revamped series already littered with romantic lapses on the main protagonist's part, the radical departure of this episode has had its way softened. Nevertheless, finding the Doctor living as a literal 'human' school teacher in 1913 England, enamoured to the school matron, is still quite disorientating, albeit in a well-articulated and quite moving way.

Before commenting on this highly promising opener to the latest - and most anticipated - two parter of this season, I'd just like to say that I do think the convenient 'chameleon device' the Doctor uses to turn his actual physiology human is a really hard concept to swallow: it seems impossible in theory, as in, how can it actually turn his two hearts into one (which it does of course, as witnessed in the scene when Redfurn checks his heartbeat(s)? Plus, why hasn't he ever used it before? Like when he was fleeing the Black Guardian for instance? This idea really does stretch us from the outset in terms of credibility. However, when an episode is generally as impressive and beautifully made as this, I'm almost beyond caring about the logistics. (One might also now use the concept of this device to argue that the clumsy revelation in the 1996 movie about the Doctor being half-human could be explained by him altering his bio-makeup in order to try and avoid detection from the Master in said story - though clearly in that case he half-botched it...)

This is one of the most filmic episodes done so far and the opening shot of the school to the choiring of 'Yee who would most valiant be' was inspired and reminded me of the classic TV series To Serve Them All My Days. Indeed, Tenant's teacher, Dr John Smith, could quite easily fit the part of said series' cheif protagonist, David Powlett-Jones. 21st century hairstyle aside (they could have gelled it down for this episode really couldn't they?), Tenant very much resembles and acts the part of his disguise, though one of course he has necessarily forgotten to be a disguise, truly believing himself to be the earthling teacher, who is disturbed by strange dreams of time travelling adventures.

This premise is one of the most superb ever thought up for Doctor Who (I know, it's based on Cornell's 90s novel), and in terms of developing the Doctor in a very new way, a truly unique scenario in the entire series' history (a sort of Superman III/Last Temptation of Christ outing for the Timelord). It is handled with great delicacy and feeling here: the romance with Nurse Redfurn is believable, gentle and actually moving, helped by Murray Gold's most/only accomplished music so far, which captures - for once - the mood of the episode. There is none of the adolescent sloppiness of the Doctor/de Pompadour liaissons of the otherwise well-realised Girl in the Fireplace of last year. This is a rather awkward, innocent and abstract love affair (bar one kiss this episode, which too was done believably), perfectly fitting the more sexually restrained Earth period. And for once the Doctor seems to be attracted to someone whom one could conceivably understand him liking: a kind, intelligent woman who oozes humility. The shots of the very convincing and detailed notes and pictures of Smith's time travels are beautifully choreographed, enriching this immaculately realised episode with extra poetic leaven.

The mysterious schoolboy is excellently portrayed, a real Little Father Time (re Jude the Obscure) - if only they'd though to nickname him that, so appropriate too - if I ever I saw one, harrowed-eyed and silently knowing, surely either an alien, a young Timelord, or some sort of younger version of the Doctor? We'll find out next week...

This apparently trapped 'alien' English schoolboy of course is very reminiscent of Turlough in Mawdryn Undead, a story also set in a public school. But what is even more challenging about this episode - and too in common with Mawdryn - is the focus on what might be described as 'the Doctor having a nervous breakdown', as opposed to the Brigadier's literally alluded-to crisis in said Davison story (another case of amnesia). Brilliant treatment of Tenant here.

The elder, Flashman-esque prefect is also an engrossing portrayal, even if he goes a bit too far with some of his lines, overdoing his RP. But he really is a menacing-looking young actor, with his goggling eyes and resonant voice to match. Some shots of him are truly disturbing.

Not so impressive are his two fellow 'family' members and one can't help feeling RTD had a hand in casting them in these roles, echoing his rather childish preoccupation with portly villains (see, well, maybe don't see, Aliens of London). At one point I seriously worried they might have written in those interminable Slitheens into this - that would truly wreck the story.

The scarcecrows! Well, these have to rank as one of the most evocative and creepy monsters ever done in the show (old or New), alongside the baroque clockwork robots in Girl in the Fireplace. Indeed, these scarecrows actually move like clockwork, lurching clumsily forwards with their heads lolling to the sides, a macabre posture duplicated eerily in the humanised 'family'. The shot of the first scarecrow moving its hand on the top of the field is a classic series shot - as are the subsequent rampages. Excellently realised creatures - one wonders why the old series never used such a potent disguise for aliens (the nearest they got was the Master stuffed with straw in Mark of the Rani).

Human Nature does of course have its clumsy lapses (as do all the stories of new Who so far, even the best ones; ie, Dalek (the Doctor with the gun), Impossible Planet (the Doctor's hugging session) and so on): tenuous humanisation plot device aside, we also have aliens firing rather wieldy and cartoon-like ray guns, and a pointless scene in which Martha moans to herself about why the Doctor had to fall in love with a human woman who wasn't her. If this is going to be the extent to Martha's characterisation, I rather hope the recent rumours of her being axed from the series come true (sorry Freema).

But slight quibbles aside, this is a beautifully shot, acted and written episode, and will in time I am certain be regarded as one of the all-time classics in the entire cannon of Doctor Who (though still not quite on a par with Deadly Assassin, Caves of Androzani, Genesis of the Daleks, Pyramids of Mars, Seeds of Doom or Kinda, in my view). But this of course depends very much so on how it pans out and concludes next week! One has grown quite accustomed now to striking first episodes and flatter finales, but I think and hope that with the emotional depth and uniqueness of Cornell's highly ambitious plot, we shouldn't be let down this time.

This season keeps getting better (bar the ok but rather empty filler 42). Human Nature is the best episode of the series so far (and up against strong competition such as Gridlock, Daleks in Manhattan and Lazarus), and arguably of new Who altogether. But as I say, how it concludes next week will very much determine its potentially great status as a complete story. Still, at least we have one episode so far which already achieves greatness in itself.

9.8/10

Now this is more like it; a beautiful, properly-paced old-style adventure that really shows up the frantic one-episode runarounds like 42 and Lazarus as the empty vessels they are - and this story actually has a decent central premise that makes it both unlike anything that's been attempted before, and oddly remensicent of the slow-burning more surreal adventures of early Davison.

A lot of the reason this 2-parter works so well, I think, is that it is finally structured like an old-school 4-parter (so far at least). Whereas some of the previous doubles have just been extended episodes 1 and 4, with the first half all slow build-up and the second collapsing into 45 minutes of frantic resolution, as it stands Human Nature is a perfect tradational 1 and 2, with the scary scarecrows arriving at almost bang-on the half way point in time for what would have been a cliffhanger.

Oh yes! It's all just so wonderful up to that point. The acting, the atmosphere, the delicately woven plotting, the nostalgic nods to the show's past. And just when you think it can't get any better, a bunch of scarecrows turn up and start rampaging about with their own patent Wizard-Of-Oz-gone-bad lollop. There's nothing scarier than animated scarecrows, not even clowns, so why it's taken them so long to mine this particular source of kiddy nightmares is a mystery.

Another important reason this story is such a triumph is that it's just so different. I've recently been bemoaning the profusion of urban-set adventures and lack of anything rural during RTD's reign, and bingo - a little English village, country folk, woodland... I've also been getting a bit bored by the regularity of alien invasions and large landmarks becoming illuminated, so again this is looking very promising in that respect. Only "The Family" themselves feel a bit standard, shooting innocent bystanders like the Judoon and generally over-acting in their first scene (all very high school drama class, the weakest moment for me), chewing their dialogue like any number of other invaders.

While we're on weak moments, the bit with the piano was silly but didn't overtly bother me. Only yet more Rose-based mooning soured the cream a little, but only a little. It passed quickly enough.

David Tennant was at his best yet, playing the likeably vague school teacher with total conviction; the scene with our hero coolly overseeing the machine gun practice, and authorising the young lad to be beaten by his colleagues were chillingly out of character. Two honourable special-mentions for me must go to Spaced's Jessica Hynes, who would make a wonderfully different companion were she allowed to stay on - the most enjoyable companions from the original series were often those from very closeted backgrounds having their eyes gradually opened by their travels with the Doctor; and a straight-laced woman in her mid-30s in the TARDIS would be a delight - and an unexpected left-field treat in the form of Murray Gold's score, not the usual metallic pomp and bombast at all. The strange piece of music which accompanied Martha's visit to the TARDIS sounded like a Burt Bacharach instrumental from the 1960s, while the waltz at the village dance was just lovely. Not to everyone's taste, of course, but I like that kind of thing.

So, on to the references. Nods to the past in Doctor Who have a habit of seeming either crassly smug (the horribly misjudged "new science fiction series" moment in Remembrance Of The Daleks), or just shoehorned in for the sake of it. Here they were perfectly balanced; the nostalgic trawl through memory lane combined with the Doctor-becoming-human plot, this almost felt like what the last episode ever would be like. I'm sure I haven't spotted them all, but these are the ones I noticed:

The biggest reference has to have been Mawdryn Undead: a regular character, having taken a post teaching in an all-boys public school, loses all memory of his past adventures; meanwhile one of the pupils is not all he seems. On the same track, the scene between "John Smith" and the young boy is very very reminiscent of a similar scene towards the start of An Unearthly Child. Then there's the cricket ball stunt from Four To Doomsday. The gag about Gallifrey being in Ireland is a reference to at least one Tom Baker adventure (I forget which). There's a musical nod to Remembrance Of The Daleks with the little girl. And the cockle-warming namecheck for Verity Lambert and Sidney Newman, which could have been toe-curling in the wrong hands. I'm sure there were many others too, and I'm equally sure other reviewers will point them out.

I'm almost nervous to watch next week's episode, I desperately don't want them to blow it. As it stands, I would say this was the best Doctor Who episode since the Davison era, perhaps even Hinchcliffe's Tom Baker years. I'm told this story comes from a spin-off novel predating the RTD era; if so it shows in the depth and richness of the adventure. The only depressing thing is that they could and should have been making stories of this calibre sooner. This is how it's done!

With the sixth episode we are plunged back into Martha's world. A world of DNA experiments and mysterious men in black. Stephen Greenhorn takes the standard comic book cliches, invoking 'Spiderman' and 'The Hulk', pays homage to the venerable Nigel Kneale's 'Quatermass' and SF B movies such as 'The Fly' and then plugs it into the main themes now beginning to run through the series - what does it mean to be a human, is there hope in a callous age and can those blessed with the gift of immortality have real faith?

Richard Clark again shows how good he is with visual composition here with lots of tracking and overhead shots, a particularly stunning revolving shot (an homage to the 'Alien' films) as the CGI monster climbs the ceiling of the corridor, and some lovely bits and pieces glimpsing characters through arches and doorways in the cathedral. He gets a great deal out of the laboratory setting too, using reflections and back-lighting to great atmospheric effect. Another very handsome looking episode.

Book-ending the episode are two scenes between the Doctor and Martha, one where the Doctor simply feels it is time to let go and one where he finally understands that Martha doesn't wish to be left behind. In between these two points, we have a narrative in which Martha plays a significant role - being resourceful, using her skills and finally going back into the conflict to face the consequences and ultimately to the cathedral where she offers herself as bait to lure Lazarus to his destiny. I don't think the relationship between the Doctor and Martha is a carbon copy of the one he had with Rose. This is more about being an equal, facing the odds with intelligence but perhaps with a pinch of unresolved sexual tension. More Martha Peel to Doctor Steed, I think.

Below the monster runaround there's also a great deal more going on.

Lazarus and his laboratory represent the scientific principle when it comes to extending life. To him it is a matter of DNA manipulation, patenting the idea and raking in the cash. The DNA manipulation machine is more or less Lazarus' electronic God. Aptly, when Lazarus takes his spin in the machine, he isn't resurrected and given new life but merely reduced to the function of the Grim Reaper itself, bringing death and destruction to himself, his wife and others. Rather than enhancing life, he subtracts and extinguishes it.

However, as Lazarus may see death as the end of the lane as far as the journey of life is concerned, the Doctor understands why the human span must end. Death to him is seen as a valuable experience for human-kind, one that he himself seems to crave here. He sees death as not just something the body must face but also as something the entire being must embrace. It's something he has been denied and where prolonged life is a curse jn which mortals he has dearly known wither and die. Immortality is regret, sorrow and loneliness.

Lazarus' transformation is an opening of Pandora's box in a literal sense when he uses the machine. 'Tonight, Matthew, I'm going to be Orpheus in the Underworld' - cue dry ice and a personification of the circle of existence, the self-devouring worm muching up mankind.

The final showdown in Southwark cathedral, superbly played between Gatiss and Tennant, reverses the cold, analysis of the flesh as seen in Lazlabs for the echoing magnificence of faith's cradle. Where the lab maybe Alpha, the cathedral is Omega - a physical playing out of life's paradoxes, of beginning and ending - and the cathedral with its stained glass, vaulted roof and resonating sound is where Lazarus has a chance to empty himself of his ego, abandon hubris and rely on faith and hope to see him through to the end of his days. It's continuing a religious theme, centred on the transformation of mortal beings through ascension and faith, first intimated in 'Gridlock'.

So, kudos to The Mill once again for their CGI monster. Not bad at all, particularly in the scene where it's scuttling along the cathedral roof. This and Gatiss' very physical performance helped us to imagine the transformation scenes without actually having to spend lots of money showing them. The make up for Gatiss was exemplary and he found ways to work with it to create the character fully and to the extent that in the end we understood Lazarus' folly and sympathised with his failed desire in the sad coda of the death scene.

It was a good, slightly old fashioned monster romp, with even a 'reverse the polarity' nod thrown in to underline the Pertwee vibe, and it often veered into camp with Gatiss (very Julian Glover like) and Thelma Barlow deliciously crossing swords. Martha's family were fleshed out effectively and her mother Francine, played with seething suspicion by Adjoa Andoh, provided a pleasant flash back to the infamous Jackie Tyler slap and offered a tantalising glimpse of future betrayal perhaps. Tish Jones was effortlessly provided by Gugu Mbatha-Raw and I'd like to see more of Leo Jones played by the lovely Reggie Yates. They all provided the necessary grounding for the Martha character, an indication of future loyalties, without ending up being a re-hash of the Tyler clan.

Tennant and Agyeman were excellent, the interplay in Martha's flat a specific treat, knickers and all! And finally, Martha is welcomed as a fully paid-up crew member after a string of episodes that have drip-fed us the unresolved nature of their partnership. With more mentions of Saxon (Harold) here and an extended trailer for the second half of the series, I get the impression that events are going to move up a gear now.

After bestowing praise upon each and every one of the first five episodes this year, last week I promised that I would try to find fault with "The Lazarus Experiment". Whilst the above was said entirely in jest, I did watch this week's episode with a particularly critical eye and, if I'm honest, there were one or two things in this episode that I wasn't especially happy with. On the whole though, "The Lazarus Experiment" is another good, solid episode of new Doctor Who. It may not be up there with some of the 'modern' classics, but it was the best thing on British Television all week by light-years.

I think it was in the pre-season Radio Times where I read that Russell T. Davies wanted this episode to have a 'comic book' feel, and if that is the case then it is a sentiment that has definitely transferred onto screen. Confidential made a big deal of "The Lazarus Experiment" paying homage to the James Bond movies, but tuxedos and gadgets aside, that wasn't really something that I bought into - Bond isn't Bond without scantily-clad women and guns! However, the comic book vibe I did get. The beautiful settings ? first in the Welsh Senate Building ('a laboratory in London') and then in a Cathedral ? both had D.C. or Marvel stamped all over them, and even the characters' names reeked of the genre. Doctor Lazarus. Lady Thaw.

"Ladies and gentlemen, I am Richard Lazarus. I am seventy-six years old and I am reborn!"

Thelma Barlow's role as Lady Thaw was much smaller than I expected after all the hype. Unlike 'Mavis' though, Mark Gatiss was given ample opportunity to shine. The chance to be in his favourite show has been something that Gatiss has waited a lifetime for and, although he might not have been cast in the dream role itself, here he gets to sink his teeth into a quite sinister role that could have been written just for him. Who knows, perhaps it was?

The sparring between Gatiss and Tennant is an absolute delight to watch, especially for someone like me who loves The League of Gentlemen as well as Doctor Who. At times their banter reminded me of how I felt watching Simon Pegg and Christopher Eccleston verbally batter each other in "The Long Game", an episode with which "The Lazarus Experiment" has much in common.

When in prosthetics, Gatiss is indistinguishable from any seventy-six year old man you may see in the street. His voice and his gait also help to get across this elderly, almost grandfather-like character. However, following his transformation I did have a bit of difficulty taking Lazarus seriously ? why in the blue hell did they make him look like Dr. Chinnery? I kept expecting him to stick his hand up a cow's backside!

Richard Clark's direction has to be praised, as does the sterling efforts of the production designers and of course, the Mill. From start to finish "The Lazarus Experiment" is visually spectacular. The C.G.I. in this episode is superb; not just in relation to the obvious but also in relation to some of the scenes inside the Cathedral and even the eponymous experiment itself.

I hope I'm not being too harsh in saying that it is really the effects that carry this episode ? the way the monster's mouth opens outwards; the horrific, calcified remains of it's victims; that breathtaking corridor chase that sees the monster spin around 360? as it runs after the Doctor. Some of the shots in the episode are on a par with some that we saw in "Tooth and Claw". In fact, my only criticism of the effects has to be that the monster's mouth didn't seem to move very well at all with the dialogue ? I noticed that they cut away from the monster speaking very quickly. Nevertheless, such a small detail could not detract from such a first-rate effort. I have a feeling that the Lazarus monster is one destined to be long-remembered. Do you remember the one with??

"He seems so human again. It's kind of pitiful."

This brings me to my main problem with the episode. "The Lazarus Experiment" is a good old-fashioned monster mash, and there is nothing at all wrong with that. However, in terms of plot there seems to be very little going on. Stephen Greenhorn has really made a lot out of the drama stemming from the prescence of Martha's family, but the science-fiction element that is driving the story is very simplistic indeed. Greenhorn may touch upon Lazarus' reasons for wanting to live forever, but his back-story is rather predictable and, if I'm brutally honest, dull as dishwater. Gatiss deserved better, really.

That much said, Greenhorn really hammers home the mysterious Saxon's hand in all this. If the rumours about his identity are true, then his interest in Lazarus' work is hardly surprising considering how he has always desperately clung on to life in the past. Looking back on this episode at the end of the season, I'd be very surprised if - as was the case with "The Long Game" - it did not come to light that there was much more going on here behind the scenes. As a stand-alone episode though, I have to say that the story feels distinctly lacking.

"A longer life isn't a better one. In the end you just get tired. Tired of the struggle. Tired of losing everyone that matters to you. Tired of watching everything turn to dust. If you live long enough, the only certainty left is that you'll end up alone."

But as I've said, what this episode lacks in storyline it more than makes up for in spectacle. The final showdown inside Suffolk Cathedral is a thing of beauty in so many ways. The Doctor's eloquent speech. The near-religious imagery of Lazarus naked in the shroud. The Doctor's nod to Spinal Tap: "We need to turn this up to eleven..." Martha hanging from the bell tower. Fantastic!

Looking at the larger story arc for a moment, "The Lazarus Experiment" marks something of a watershed for Martha Jones. It sees her return home for the first time since she begun her travels with the Doctor, and it also marks the first appearance of her family since "Smith and Jones".

"He's dangerous. There are things you should know."

In direct contrast to his navigational cock-up back in "Alien of London", here the Doctor actually gets Martha home within twelve hours. He still manages to earn himself a slap from Mrs. Jones though - "All their mothers. Every time!" ? as throughout the episode she has some sort of 'secret service' bloke whispering in her ear about the Doctor and how dangerous he is. Even so, I think that in this episode Francine comes across as very unlikeable - I can certainly sympathise with Martha's Dad! Even in her fiercest moments, Jackie Tyler was always loveable. Adjoa Andoh portrays Francine as much more austere; a much tougher nut to crack in many ways.

"I know the age thing's a bit weird but it worked for Catherine Zeta Jones."

Martha's sister Tish is also given quite a bit of exposure in this episode, and whilst she is not as severe as her Mother, she comes across as a bit 'up herself' and even a bit shallow. Prior to Lazarus' transformation, Tish won't even give him the time of day, yet as soon as he becomes a handsome young(ish) man, she's all over him! However, it is important to note that at the end of the episode she's there for Martha to catch her when she falls. Literally.

Of the Joneses, only Leo acquits himself as a pleasant, well-adjusted young man, though I suppose it's early days! Jackie, Mickey and Pete really endeared themselves to the audience over the course of the first two years and so I think that the Joneses have a difficult task in trying to replace them. So far, so good though.

I enjoyed the final scene very much. It sees Martha become a 'proper' companion as opposed to a mere 'passenger', much in the same way that Rose 'signed-up' properly at the end of "World War Three." "Okay," says the Doctor, nodding towards the open TARDIS door. "Well, you were never really just a passenger were you?"

And so off they go; off into the forty-second century.

"I'm begging you. I know who this Doctor really is. I know he's dangerous; you're gonna get yourself killed! Please trust me. This information comes from Harold Saxon himself. You're not safe."

On a final note, I'd just like to say 'bloody Eurovision!'

I suppose if you do have to stall the season for a fortnight, then this semi-cliffhanger is a tantalising way in which to leave things, especially when combined with the new Christmas Special-style trailer for the rest of the season. It seems that there is certainly much to look forward to ? Captain Jack back in action; Saxon in an oxygen mask tapping the desk, evilly; a dark and gritty 'real time' adventure out in space; not to mention the "Human Nature" dramitisation. I haven't read the novel for a while, but I don't remember Scarecrows or a Wedding! They certainly seemed to have jazzed it all up a bit for TV, even the Aubertides look far more threatening on screen than I imagined when reading the book.

"He's fire and ice and rage? Loves greatly, but not small-ly. He's Merlin."

Roll on Saturday week!

I wasn't particularly looking forward to this episode to be honest: all-too-obvious mad scientist plot with all-too-obviously named professor, return to Earth, reappearance of plastic Martha's plastic family, CGI monster and so on. All the ingredients for the kind of irritation, boredom and cringing I normally experience during your average New Who episode.

But I was pleasantly surprised by The Lazarus Experiment. Of course it still had token annoyances which have become something of the RTD production-tradition now, but this particular story managed to rise above such irritant factors due to a general seriousness of tone and a well-articulated - albeit not entirely original - plotline.

From the outset, boundaries were being put down by the maturing Doctor towards his latest and rather simpering companion, Martha: for once we had a reason, more like the old days, for the Doctor to return his companion to her time on Earth: he wanted to call it a day and put her back we he found her. And who can blame him? Martha is even more insipid than Rose, but seemingly lacking the latter's attempt at a personality. Martha seems to have none at all. Her fancying the Doctor just seems substanceless and token in its doe-eyed vapidness. There's no chemistry at all anyway. So I thanked God that the Doctor started this episode further emphasising his emotional detachment from her. If only she hadn't hopped back on at the end (but that was his fault admittedly).

This scene also adds a welcoming touch of alienness and detachment to the rather erratically scripted 10th Doctor, and this is greatly welcome. This slightly restless and solipsistic slant on Tennat's incarnation is also nicely reminiscent of early Pertwee's misanthropic fuss-pot of a Doctor, who had childish tantrums whenever his attempts to regain control of the TARDIS for purposes of self-centred escape from his rather mundane UNIT trappings backfired.

This is, in many other ways, very much Pertwee-era territory (sonic screwdriver aside): the 10th Doctor, just like his ever doomwatching 3rd incarnation, pops along - in tuxedo too - to witness the latest amoral experiment turning heads in the human scientific community. In this sense this episode is very reminiscent of the enthralling thriller of Season 8, The Mind of Evil. We also have the ultimate fan reference to the 3rd Doctor: 'reverse the polarity of the neutron flow'.

What I liked the most about this episode wasn't the plot itself, but certain concepts and chunks of explanatory monologue from the Doctor, which added real leaven to what could have otherwise degenerated into a facile run-around. The suggestion that the regenerative process of Lazarus's machine should produce an atavistic reaction in the human body, tapping in to an evolutionary cul-de-sac wherein our genes still contain an aborted DNA chain which could have led us to evolve into scorpion-like insects rather than apes (and then humans), was the stuff of classic Who, and really did add terror to an otherwise ambitious but only half-convincing CGI monstrosity (the body was good, but the air-brushed-on face really didn't work for me, and just looked like a computer graphic, and also not remotely like Gatiss himself) - I think CGI should be scrapped entirely now, and more tangible model work should be employed: the similar man-headed spider creature in the Eighties version of The Thing for me is far more convincing than The Mill's efforts nearly a quarter of a century later.

But what really carries this story is the consumate performance from Mark Gatiss in the title role. In Professor Lazarus, we have, in my mind, the first really charismatic and affecting foil for the Doctor since the new series began. The character is in some ways reminiscent of Julian Glover's immortal turn as Count Scarlioni in the classic City of Death. And of course Gatiss is well aware of his classic lineage in this regard being an out-of-the-closet Whovian himself. He pulled out all the acting stops in this episode, in quite the opposite fashion to how 'Trigger' pushed them all into ham as Lumik in Risable of the Cybermen last year. Gatiss shows how a Who villain should be done: with suave menace and a subtle hint of self-torment. But where Gatiss's performance, and indeed the entire episode, really comes into its own, is during the cathedral scene, as Lazarus cowers in mutating pain naked in a red towel on the flagstones, in a battle of philosophies with the Doctor. This scene was exceptionally well-directed and acted: darkly, subtly, but above all, dramatically. This scene also reminded me a bit of the 5th Doctor's final confrontation with the mutating Omega at the end of Arc of Infinity (and is it just me, or does the young Gatiss bear a vague facial resemblance to Peter Davison?). During this scene also, there is a pivotal and highly resonant retort from Lazarus to the Doctor's comparatively superficial observation of how 'facing up to death is part of being human' - which of course is imutably true; but Lazarus comes back with an equal truism about our contradictory condition: that it is also our instinct to 'cling to life with every fibre of our being' (sic). Even the goggle-eyed 10th Doctor seems struck dumb by this statemtent. Excellent scripting. Here then we have a tale suitably grisly and morally-disturbing as its obvious literary influence, Dorian Grey.

The only trouble that crops up here is that Gatiss frankly steals this episode from Tennant - and though Tennant strains to rise to the occasion - and doesn't do too badly in places -there is no doubting in my mind that this was one occasion, and actually probably only the third of three occasions for me in the show's history, when an incidental actor in a Who story seemed to have 'Obvious Doctor material' stamped all over him in comparison to the current incumbent (the other two occasions for me were Paul Shelley opposite Davison in Four to Doomsday, and David Collings opposite Davison (again, sorry Peter) in Mawdryn Undead). I know Gatiss has long nursed a fantasy of one day playing the lead - partly pampered to in his comedic cameos in the 30th Who anniversary documentary), and this is a potential I haven't been convinced of myself previously. However, on the basis of his turn in this episode, I did feel instinctively that he was more obvious Doctor material than Tennant. In his very RP, throaty delivery of lines, Gatiss oozed the kind of old-style theatrical gravitas that has so long been missing from the Timelord's interpretations. As the young Lazarus, I detected also a passing resemblance to the young Derek Jacobi (turning up of course soon in Utopia, which is tops with me, being a massive fan of I,Claudius, especially of Jacobi's eponymous performance).

The musical extermination of the Lazarus monster was indeed 'inspired' as the Doctor put it - and the sight of him grinding away at the church organ as a means to defeating one of his foes has to surely be one of the most, well, artistic ways in which the Timelord has ever won the day. Definitely inspired.

Subtle hints at the inevitable identity of the mysterious Mr Harold Saxon aside, the other key factor of this episode which I think deserves particular mention and praise, is that for practically the first time since new Who began, we have the Doctor finally using a more erudite and profound cultural reference properly befitting the drama of the occasion than bathetic trendy allusions to Kylie Minogue lyrics or third-rate Eighties films: 'not with a bang but a wimper - Eliot. I also liked the subtlety here of saying 'Eliot' rather than 'T.S. Eliot' - not even spelling it out. This was a truly welcome return to the more profound and poetic days of the glowering 4th Doctor (cue his tendency to quote poetry, as in The Face of Evil and at the end of Horror of Fang Rock). Again, brilliant scripting. And what a polar contrast to the usual contemporary cultural allusions.

To sum up then, this episode certainly didn't go out with a wimper, as I was starting to suspect it might about 10 minutes before its end, with a red-herring conclusion of Lazarus being stretchered away in an ambulance - but the episode hit back with a real vengeance and a philosophically challenging denouement which in itself (that cathedral scene) will, to my mind, go down as a classic moment in the series (both old and new).

Like Gridlock, another pleasant surprise of an episode, The Lazarus Experiment continues to show how unpredictable this season is turning out to be. This is not necessarily a classic story, but it certainly contains some unexpectedly classic moments, which is the next best thing. Mr Gatiss, I'd hand you the keys to the TARDIS any time.

7/10.

42 could only have ever gone one of two ways for me. After a fortnight's deprivation, this episode was either going to satisfy two weeks worth of pent-up cravings or it was going to crash and burn. Now whilst the Pentallian may have avoided that particular fate, in my opinion Chris Chibnall's episode did not.

To try and focus on the positive, I enjoyed Joseph Lidster's prologue that he posted on the official Doctor Who website last weekend. It took me back to the days of the Doctor Who Magazine / New Adventures prologues, which is quite fitting considering that we are headed back into Virgin territory next week.

I should also say that I love both the gimmick of "42" and also Chibnall's cryptic episode title. A 'real time' Doctor Who adventure, 24-style, is hardly unprecedented but it's definitely a first for the TV series. And unlike the advert-ridden 24, "42" is actually an adventure set in real time. No three-minute recaps. No commercial breaks. "42" clocks in at just under forty-five minutes (a good six or seven minutes longer than most episodes of 24) and they truly are forty-five minutes of real time action.

And as for the title, it has so many possible connotations. We have the obvious ? "42", because at the start of the episode the Pentallian has just over forty-two minutes before it will crash into a star. "42", because the episode is (supposedly) set in the forty-second century. "42", because it is the meaning of life, at least according to Douglas Adams, and in his novel The Restaurant at the End of the Universe his characters face a similar dilemma to the protagonists in this story. "42", because it's 24 backwards, a television series which this episode emulates in microcosm. And "42", because Russell T. Davies wanted to chuckle at the Radio Times billing: 42 7/13.

"A playful title" doesn't quite cover it. It's almost X-Files worthy.

However, a clever title alone does not a good episode make and more importantly, in a real time setting it is vital to keep things moving quickly and keep things interesting. Watching 24, for example, I often find it hard to believe how quickly the minutes tick by; so much so that I have my doubts about just how accurate that ticking clock actually is. In "42", unfortunately, I experienced the polar opposite sensation. I thought they'd slowed the clock down! 34 minutes to impact? You must be joking?

"The wonderful world of space travel. The prettier it looks, the more likely it is to kill ya."

If nothing else though, visually "42" is a thing of beauty. The red, orange and brown grading really helps the viewer feel the heat. Both the look of the episode and some of the plot elements reminded me very much of last year's superb "The Satan Pit" two-parter, but sadly I found "42" to lack the same punch. Both stories see the Doctor in a situation that he has never really been in before ? which after nearly forty-five years has to be praised! ? but whereas "The Satan Pit" put the Doctor up against the Devil himself, "42" can't decide whether it's baddie wants to be Darth Vader from Star Wars or Cyclops from X-Men. That's if it's a baddie at all, when you think about it?

David Tennant made me laugh on Doctor Who Confidential when he said that Michelle Collins "in a vest and smothered in baby oil" was one of the best things about the episode; with that I can agree wholeheartedly. The vest and the baby oil help, obviously, but so does Collins' wonderful performance. She certainly makes the best of a very poor script, as does Graeme Harper with his direction. One of the most memorable scenes in the whole episode sees McConnell open the airlock and have herself and what is left of her husband blown out in to space. The shot of them both floating above the sun is a stunning and powerful image, romantic even.

Similarly, David Tennant and Freema Agyeman both give phenomenal performances. "42" documents Martha's first trip in the TARDIS as a 'proper' companion, as it were. She gets her phone jazzed up by the Doctor ? "universal roaming" ? and, in one especially emotional scene at the end, he gives her the key to the TARDIS. Most important of all though, "42" sees Martha truly step up to the plate and become the Doctor's equal.

MARTHA You don't know the Doctor. I believe in him.

RILEY Then you're lucky. I've never found anyone worth believing in.

First of all, it is down to the Doctor to save Martha. Once again, Harper excels in his direction. The escape pod is jettisoned and Martha drifts silently and gracefully away from the Pentallian; no music, no sound. It's another beautiful piece of television.

"I'm scared. I'm so scared? it's burning through me."

And then Martha has to return the favour, just like Rose always did. Here though, I concede that this does feel just that little bit more important. I couldn't say for certain ? believe it or not I can't quote every single Doctor Who story verbatim ? but I'm pretty sure that the Doctor hasn't freely admitted to being afraid before and even if he has, he has certainly never cried out that he's scared as he does here. Sure, he's said "I know, me too" and things to that effect, and I do remember reading Andy Lane's New Adventure "Original Sin" and being gobsmacked to see the Doctor admit to being afraid of death, but this is really something else. To coin a phrase, this is a fate worse than death; the Doctor's worse nightmare. Worse than the Valeyard. He'd not only become a killer, but a mindless killer.

And to be completely fair to Chibnall, from T-10 minutes and onwards "42" improves dramatically. It is like suddenly someone has turned up the volume to eleven! The scenes with the Doctor on the outside of the ship, where he first becomes infected, are breathtaking, and Murray Gold's score really kicks in full force. The momentous piece of music that we first heard a fortnight ago accompanying the 'coming soon' trailer is used here with spectacular effect. I'm something of a soundtrack connoisseur ? nothing beats John Williams' Star Wars Trilogy score in my book but, especially when you consider that he is prolifically churning this stuff out for episodic television, Murray Gold can't be far away from such greatness.

"It's alive? that sun's alive? a living organism. They scooped out it's heart, used it for fuel and now it's screaming? it's living in me. Humans! You grab whatever is nearest and bleed it dry!"

There were a few other things that I did enjoy about the episode. The shot where the light leaves the Doctor's eyes towards the end stands out as a superb bit of C.G.I., and I also liked the pub quiz-like fashion in which Martha and Riley had to try and open the bulkhead doors. The Elvis vs The Beatles question was good fun, especially the 'classical music' joke ? a nod to Vicky's comment in "The Chase", perhaps?

MARTHA: It was nice, not dying with you. I think you'll find someone worth believing in.
RILEY: I think I already did.
[Snog]
MARTHA: Well done. Very hot.

I also liked the fact that Martha got to have a bit of thing with Riley. Until now she's been a bit of a doormat for the Doctor really, but at the end of "42" she certainly wastes no time with Riley. What I'm not sure about though is whether the Doctor saw their kiss or not on the scanner. Inside the TARDIS he's clearly very shook up about what he has just been through, but his vacant expression says more than that. Much more.

"Have you voted? Mr. Saxon will be very grateful."

For me, the most interesting part of "42" was the whole Martha's Mum / Mister Saxon segment (Hang on, Mister Saxon? Isn't that an anagram of Master Number Six?) I'm developing a massive dislike for Martha's mother (just as I'm supposed to), and although whether she is being leant on by Saxon's people or whether she is happily assisting the sexy and sinister Miss Dexter (Elize du Toit) in her investigations is unclear, things are certainly getting very interesting very quickly. It's 'Election Day'?

Whilst I'm on this point, was it my imagination or was is it Phil Collinson playing Miss Dexter's bodyguard on the left hand side of the screen?

So in the light of the above, why do I not have a higher opinion of "42"? In short, because I think that the plot is absolute rubbish; words like 'dreary' and 'predictable' do not do it justice. Ten minutes of high-octane action at the end cannot excuse over thirty minutes of tedium. I really cannot get my head round how Chibnall could write four of the best hours of British television in recent memory ? the fantastic Torchwood episodes "Day One"; "Cyberwoman"; "Countrycide"; and "End of Days" ? and then when he gets the chance to write for the big one, to write for Doctor Who, to screw it up so utterly! It's tragic really as all the other elements in "42" work so well ? all the actors' performances; the direction; the effects; the music?

A waste.

In fact, so massive was my disappointment with this episode that I would go so far as to say that it is not only the worst episode of Series Three so far, not only the worst episode of the new series so far, but the worst televised story since "The Greatest Show In The Galaxy" back in 1989. Even the Confidential team, who have until now this year quite comfortably filled their expanded 40-minute time slot with new series material, had to resort to a lengthy trip down memory lane to examine the spaceships of the classic series.

However, I am often guilty of reactively judging episodes a little too harshly only to have them grow on me over time. To make doubly sure, I watched "42" again this morning and again, I got bored after about three minutes.

Furthermore, I haven't seen such a divide in the opinions of fans since "Love & Monsters" aired last year. I posted a bulletin on www.myspace.com/historyofthedoctor to ask my friends on there what their thoughts were, and comments ranged from 'one of my favourite episodes' and 'a future classic' to 'a bit of a disappointment' and 'total let down'. I guess it all depends on how you like your Doctor Who ? I admit that I'm not usually into the hardcore sci-fi episodes (unless they are particularly strong on the human element).

So whilst "42" certainly has it's fans out there, in my book at least the new series producers have churned out their first true clanger. For the first time since 2005 I have to say that this week, Doctor Who wasn't the highlight of my viewing ? an especially hilarious edition of Friday Night With Jonathan Ross (incidentally featuring John Barrowman and an exclusive clip of "Utopia") has stolen that honour.