And "Father's Day" is very much a rollercoaster. The drama starts off light and simple and then twists and turns through a variety of emotional loops, each getting more and more intense.

This episode offers a very simple premise: What if you could stop a tragedy in your personal history? It's a simple idea, and surprisingly, for something so obvious to time travel, not one that Doctor Who has really dealt with before. It's certainly not a premise that has been taken to it's full emotional potential. Here we see Rose taking a course of action that is so utterly wrong yet so utterly understandable for anyone in her situation; Rose saves her dead father and the Doctor didn't see it coming.

Father's Day works on many levels thanks to its strong character progressions. First and most obvious is Rose, who quite frankly, hasn't had the spotlight I expected her to have throughout the season. The story intelligently takes her through an emotional drama, which, despite it's highly theoretical scenario, feels real. Considering the extent of unearthly circumstances her father has to comprehend in no more than 45 minutes, his character's introduction and evolution works very well.

This is where the story scores so well. It leaves the time techno babble largely to the side and allows the script to deal with the effects of temporal damage has on the main characters. There's a lot to cover if the writing is to convince the viewer that the characters are acting realistically in such a bizarre circumstance, and Paul Cornell really does pull it off.

Shaun Dingwell does a great job as Rose's father, Pete. He breathes the humanity and realism into the character. If Pete had been miscast, the whole scenario would have fallen apart. Piper gets to show off her own emotional skills and does a fine job as always. Eccleston also delivers a solid role; however the events of the episode do somewhat weaken his strength in the lead role as the Doctor.

The Doctor is changing, and that amount is clear. One of the more subtle storylines in this episode is his isolation from humanity. It doesn't seem to occur to him that Rose might try and save her father and this seems surprisingly naive for the character. His isolation is something that Rose has noticed, and in one of her less endearing moments (but certainly one of the most realistic portrayals of a teenager on TV) she makes it clear she knows he'll never leave her and he'll be back like a lost puppy. He needs the emotional human contact she gives him, envies that gift of humanity which he never had with his people and even what he did have is now gone. In someway, it's a very touching perspective, but it does weaken both his character and mystery. Somehow it feels wrong for a 19 year old to have such power over him.

Perhaps that's one of the biggest mistakes of the new series. The creators seem insistent that Rose and the Doctor are equal. Some say that she is more than the Doctor, and that doesn't really come across. Certainly she's not so world weary, but that comes from 900 years of experience, but she doesn't quite seem the gem of humanity the writers and the Doctor see. She comes across as a teenager. Strangely, that's a compliment as there are few dramas that can write a teenager well, however there is a little that makes her seem much more than the average teenager. I don't feel that comes across in the stories as being so special - regardless of Ms Piper's constantly solid acting. She certainly has tough competition to prove her worth too. Ian Chesterton, Sarah Jane Smith, Jamie McCrimmon, Jo Grant, Barbara Wright to name a few.

Overall "Father's Day" is a very good episode. Some small niggles get in the way. There is the occasional cringe worthy time clichй. For instance when kid Mickey, Rose's future boyfriend, is focused upon; there are some remarks about how much he'll cling to his future girlfriend. There is the old "I'm sure I know you from somewhere" line between father and future daughter. These are small, superfluous script gags that were acceptable twenty, thirty years ago, but now actually bring down dialogue quality.

The music is a little over indulgent. The haunting melody that accompanies every sad moment in the episode has no subtlety in its choice of instrumentation or how it's actioned. You can almost punctuate to the second when it's about to pop in and when it does, it just feels overtly artificial.

Aside from some dubious CG and a rather predictable resolution, this episode is very good. After all, the effects, the plot and the music are backseat to the emotional drama. The drama is lead performer in this story and it performs immensely well.

It's wonderful to see this series try so many different styles of drama and pretty much hit each style bang on. Great stuff. Now, go watch it again.

I suppose I could be described as a lifelong fan of Doctor Who, having watched it since William Hartnell first stepped out of the Tardis in 1963.

However, I did lapse during the Peter Davison/Colin Baker/Sylvester McCoy years, only watching occasionally, but never really losing the bug. Then when I heard that Doctor Who was coming back, I must admit I was sceptical at first, thinking that it would probably be "Americanised" or in some other way spoiled beyond recognition. When I heard who would play the Doctor and his companion, I sank further into gloom, thinking that neither would be right for the roles.

Then came Episode One, and I was blown away.

From the second that Rose got out of bed for what seemed like another ordinary day at work, I was glued. From the second the Doctor held Rose's hand and said "Run", I was bitten. "Lots of planets have a north" will go down in history as one of the finest one liners. Since then, I have marvelled at the total believability of Chris Eccleston's Doctor, and been totally amazed by Rose's character, and the chemistry between them is magic. If this isn't already a superb platform for Billie Piper's acting ability, then it soon will be, and I expect her to be in greater things in the future, because she is one of the best young actresses this country has, and we should be proud of her - and she is beautiful into the bargain.

As each episode has been aired, the characters have gone from strength to strength. I have not seen a bad episode yet, but there has been one slightly weak one, that being "The Long Game". The secondary characters in this episode were not allowed to develop into knowable people as they have in other episodes, in particular the Editor and Cathica. However, "Dalek" was absolutely and utterly awesome, and more, and I thought it could not be bettered.

Then came Episode Eight, and I could contain myself no more.

This to me, is classic Doctor Who brought alive for todays audience, and I have to say I did not expect to see such brilliance. Shaun Dingwall has been great in other things, and is a much underrated actor, but as Pete Tyler he was a revelation. The scene where he recognises Rose for who she actually is produced one of the finest facial expressions yet - only equalled when Rose first entered the Tardis - and there have been plenty of these moments in the series so far, with each one being magic and completely believable. Rose's look of horror when the reaper devoured the Doctor on the church floor really made me feel her grief for a heart thumping moment, and was another massive piece of the jigsaw which is the relationship between the Doctor and Rose. This goes deeper each episode, reminding me somewhat of the wonderful chemistry between Mulder and Scully in The X Files, it really is quality stuff.

The continually reappearing car that eventually kills Pete Tyler created just the right level of uneasy frustration that time was somehow on hold, waiting for the event to happen, thus putting things right once more. One could really feel for him as he ran headlong, knowing he had to die for his daughter, and everyone else to survive.

Also, what's all this about Camille Coduri only being an average actress? I suggest her critics watch her episodes again. Jackie Tyler is the perfect lovable rogue who seems as if she has not so much grown up, but been dragged up, and is now trying her best to make life as comfortable as possible in the face of all these things that keep happening to her since Rose met the Doctor. Camille Coduri plays the part to a T.

Altogether "Father's Day" was as great as "Dalek", and that took some doing. It had all the things we expect from Doctor Who; an ordinary day turned bad, well portrayed secondary characters, a seemingly unsolvable problem, scary monsters, humour, dark moments, and the moving emotional scenes which are fast becoming a staple of the new Doctor Who. All these will keep me watching, but I am sorry there are only five episodes left of Chris Eccleston's Doctor, who is probably the best one in 900 years.

Eight episodes in, and I feel duty-bound to finally put pen to paper (or finger to keyboard!) and praise this series which is fast becoming one of the most consistently wonderful TV programmes I can ever remember.

It's not that the episodes so far haven't been worthy of praise; "Dalek", "The Unquiet Dead" and "The End of the World" all deserving of the gushing eulogies which have been heaped upon them, and only "The Long Game" failing, in my view, to engage in the same way the rest of the season has; but "Father's Day", while relatively predictable in plot devices right down to the climax, was without doubt one of the most perfect pieces of TV you could wish for (and do be careful what you wish for...!)

In writing, direction, and acting, this was top-notch stuff, plucking on our heartstrings in a way Dr Who has never done in all its glorious past. I hope this doesn't get lambasted by those fans who have compared Rose and Jackie's previous domestic scenes to EastEnders; this series has decided to show real, genuine, fleshed-out characters and these scenes have all been important in this respect, and I feel for the most part (though not always) they have been successful. And if it hadn't been for the audience slowly learning and empathising with Rose's personal life and history, this episode would never have been as poignant as it was. Billie Piper - wow! - she just goes from strength to strength, and without a doubt is the best companion the show has ever had. In this episode's scenes with her father, it was difficult to imagine anybody handling them better. This series has made us laugh alot and now has made us cry. Shaun Dingwall was fantastic as Rose's father, a much better-written character than I was expecting from his first few scenes, and even Camille Coduri - who I feel has been the weak link so far in the ensemble cast, more so than Noel Clarke - put in a solid performance as Jackie. The cast were all aided by a quite wonderful script from Paul Cornell, along with "Dalek" without doubt the most mature and thoughtful script of the season so far.

As we've come to expect (dare I say take for granted) this season, the effects - such as they were - were of a high quality, the Reapers being another well-realised monster for this series, despite having perhaps not quite enough to do. Of course, this was because the episode was so wonderfully dialogue - driven, with the Reapers feeling almost incidental to the plot.

And I haven't even mentioned Christopher Eccleston yet...I've read various views on his performance with interest, and can understand to an extent some viewers' irritation with the humour, silly faces etc. But was Tom Baker's Doctor - surely THE Doctor in most fans' eyes - really too far off that with his staring eyes, wide grin and jelly babies? The only problem I have had with this Doctor is occassionally with the way his relationship with Rose has been portrayed - last week's "that's your boyfriend" comment being the sort of juvenile comment which has at times sat a little uncomfortably with me - but here I felt that relationship was judged perfectly, the purile humour nowhere to be seen, and Eccleston, as with "Dalek", showing that with a little longer in the role he could have staked a very real claim to being the best Doctor yet. As it is, I feel personally only Pertwee and Tom Baker have been better - but I know that's all a matter of taste. What is beyond question is that Eccleston is a fine actor who has been consistently good, with flashes of outright superlative excellence. What a shame we're over halfway through his tenure.

Much was said in praise of Joe Ahearne's direction of "Dalek" - with good reason - but I think he's topped this with "Father's Day", creating what felt like quite a pacey episode despite the relative lack of action. And Murray Gold's music - well, I'm not a detractor of his anyway, and have been a little surprised at some of the comments that have gone his way, but I can't imagine anyone having a gripe with the incidental music for this episode - again, perfectly judged.

Yes, Jackie of 17 years ago looked like Jackie 2005 with a different hairstyle. Yes, if you look even vaguely closely, there were holes in the plot - any show that deals with changing time etc will have holes big enough to climb through (what of the driver who killed Pete, surely his life must have been dramatically changed, and surely Rose would have then grown up knowing that the driver had stopped and wasn't a hit-and-run) - but any niggling criticisms are just that - niggling - this was superbly - crafted, quality TV, setting the standards for everybody out there that works in this medium. And shame on ITV for even beginning to think that churning out yet another bunch of Z-list "celebs" for an idea that must have taken about half a nanosecond to think of - Celebrity Wrestling - would even begin to dent the fantastic ratings that this series has got.

A final word - intelligent criticism is always useful and important, but some of the whingeing comments from so-called Who fans about this series has made my blood boil, especially that aimed at RTD. Without this man we wouldn't be enjoying a series of Dr Who at all, let alone such an incredible one. Comments such as the Dr wouldn't have said that, done this, etc - yes, this is Dr Who, but it's a new Dr Who, it has changed with the times as it had to, and at this moment in time nobody knows what the Dr would say or do better than RTD himself. Russel - you are a star and keep up the amazing work!

And one final final word - have to agree about the preview of the following episode at the end of the "Aliens of London" cliffhanger - didn't work - but for the single episode adventures, this is a great hook for the next week. My jaw was already dropping at what I'd just spent 45 minutes watching when the preview for "The Empty Child" came on, and it dropped further still. From those few seconds, it looks like the most amazing spectacle yet, and I just can't wait, and can't believe that something so near-perfect can keep getting better still.

Like any field of expertise, Dr Who fandom is blighted by jargon. 'Umbrella season'. 'Cancellation crisis'. 'Season 6b'. Phrases with no meaning outside the geeknoscenti. But among them all, few loom larger than 'base under siege'.

A staple format of the Troughton era, such stories place the Doctor, his companion(s) and a selection of guest stars into a claustrophic environment, attacked from without by some malevolent alien force. Our heroes can then fret and fight off incursions for however many episodes are required, without the need for a single new idea. All you needed was a new monster (or failing that the Cybermen) and a girl with a good pair of lungs, and you were off.

But that was the 1960s. Dr Who then was action adventure, plain and simple; all fist-fights and derring do, like Robin Hood with airlocks. In 2005 the series has moved on, and its first base-under-siege story – while admittedly featuring Billie Piper's scream debut – absolutely epitomises that contrast.

>From the get-go (which these days comes in the last minutes of the previous episode), it was clear this was going to be an ambitious, high concept story. Time is damaged; trusts are broken; people die. But more than that, it was also going to be essentially a character piece, which the classic series (even in its slower under-siege moments) had little time for. Gone are the familiar Troughton tropes – A Traitor Unmasked; The Coward Endangers Us All; The Cyberman Turn Up For No Good Reason – and in its place is a tight, fiery, emotionally intense piece about the dangers and importance of self-knowledge, that treads the sort of emotional territory ordinary dramas genuinely cannot reach.

It's brilliant stuff.

Mind you, that shouldn't be surprising. The writer of this episode, Paul Cornell, is best known to fans as the author of some of the best original Dr Who novels around, and it's the same techniques that made them work that gives this one its strength. Indeed, many aspects of Father's Day – the playing around with time; the use of symbols and images; the exploration of real-world relationships and emotions (particularly guilt); the epigrammatic Doctor and the brittle, argumentative nature of his relationship with his companion; even the impact of fathers – are all core elements of the spin-off 'New Adventures' series that made his name.

These days the NAs are often summed up by the single word 'angst', and undeniably this is an angsty story. But Paul Cornell's books in particular were also known for their powerful emotional focus, and this is where Father's Day really shines. The author's trademark linguistic cleverness (Jackie gloriously describing her husband as 'an accident waiting to happen'); his attention to structure (the delicate bookending voiceovers), and the elegant, double-layered possibilities of the closing sequence would be worth nothing if the story lacked a soul. In his creation of Pete Tyler, brilliantly written as an intelligent, open-minded individual rather than a foil to circumstance, and brought to life flawlessly by Shaun Dingwall, he gives us one that's truly to be reckoned with. The fluttering, hopeful uncertainty of his relationship with Rose does a better job of depicting fatherhood than half a century of soap, and, through a series of genuinely moving, perfect vignettes, fuels a tragic story that really does have two hearts.

Unfortunately, the downside of all this is that the action adventure aspect is rather put to one side. Consequently, while the first half bundles along at a fair old pace, by the second half pretty much everything has happened that's going to happen, and there's nothing left to do except explore character arcs and just generally be besieged until the finale. And indeed, while the siege some features tremendous dialogue, as well as two of the best performances ever seen in the show, this is nevertheless essentially what happens, with lots of rather talky scenes separated only by repetitive establishing shots. In dramatic terms, the whole thing feels like it's crying out for another beat in the under-siege sequence, leaving the story simply too short on events.

It's only fair to note that budgetary constraints may have played a part in this, given Cornell's admission that after repeatedly being told to think bigger he was finally told to think rather smaller for the final draft. It's perhaps telling, therefore, that while the monsters are impressive in both design and realisation, particularly when seen as shadows flitting half-seen past windows, they never really do anything. Their cgi unworldliness, though arguably in keeping with their nature, is only heightened by their conspicuous lack of real-world interaction, and this limitation (as well as their lack of dialogue, or any visual evidence of their supposed global impact) ultimately undermines the threat. Given, too, that all the visual set-up is there for a climactic bursting-through-the-stained-glass-window sequence which never comes – and given that the whole point of setting something in a church is to have something climactically burst through the stained glass window – it's tempting to suppose that at least some of the sagginess of the final act was due more to money than to over-egged angst.

Ultimately, then, Father's Day is monumentally effective... just not, perhaps, as Dr Who. With its curiously minimal science fiction element, and touchy-feely emotions in place of rampaging monster sequences, it's hard to imagine younger audiences feeling entirely comfortable with the sudden change of pace. But while it's not quite what viewers were expecting, which is arguably no bad thing, and not quite as good as it could have been – and when has that not been true of a Dr Who story? – it remains, on its own terms, a tremendous piece of television.

As fan jargon would have it, it's rad, not trad - and it's not half bad.

It was all going so well. Unfortunately, Father's Day was the moment "New Series 1" had a rather nasty prang and ended up sprawled over the bonnet of a speeding gold Chevette.

Let's start with the good stuff. The human elements of Father's Day - and the overall premise - were brilliant. Who hasn't thought "if only" or wanted to change something in their lives, see how the world and their family was before they were born? Shaun Dingwall gave a stunning performance as Rose's dad (all the more so given the material he had to work with - more on this later) and Billie Piper was again excellent; human without being mawkish, understated without being cold, warm without being too cosy. This new, more personal side to Dr Who... y'know it could just work.

Standards of direction were high - notably the long shot of Rose's face against the backdrop of the church window - as was production, with big hair and shiny suits all present and 1987 correct. Nice little touches like the Graham Bell phone call and the car radio playing 21st century techno showed good attention to detail. And the Reapers looked fantastic with the moments before they appeared, and their ultimate revelation, genuinely spooky/scary.

However, it's somehow ironic that a Dr Who episode set in the late 1980s should fall down so badly on plot.

Simply, Father's Day made absolutely no sense at all, whatsoever. Even the Doctor couldn't muster anything approaching a sensible diagnosis for why a "wound in time" needed to be "sterilised" by crossbred vulture-dactyl things, scary as they were. Things went from bad to worse when, somehow, a 80s brickphone battery was rigged up to "recharge" the invisible Tardis, which would somehow get the damn things back in their cage, let Stuart and Sarah get married, keep Rose's dad alive and er, wipe everyone's memory. I'm struggling here.

Once again the Doctor passed the buck - here Rose, last week Adam - for events for which he bears a great deal of responsibility. More attempts to underline the doctor's 'alien-ness' perhaps, but yet again, he comes across more arrogant, selfish - and human.

Clueless too. Surely a TIME LORD would be the expert at sorting out disturbances in, er, time? This Doctor is more bodger than schemer. The sum of his character's role in this episode: has a tiff with Rose after showing off to impress her (again), runs around shouting, acts a bit miffy, sulks, apologises, then gets himself Reaper-ed. Eventually it took Tyler senior to obligingly throw himself under the damn car (why had it followed him to the church?), perhaps in hope of terminating the nonsensical turn the life-he-shouldn't-have-had was taking.

Someone in post-production should have intervened to at least ask for some attention to be paid to these problems. Here was a fine premise - meddling in time with unforeseen consequences - but one which to make convincing required depth of imagination and commitment to detail. Sadly, Father's Day had neither. In the end, this story reeked of compromise. Perhaps Russell T upped the human elements to gloss over the holes, perhaps the writers didn't credit the early-evening audience with the intelligence to follow a complicated idea. Perhaps it's enough for children to have an attack of flappy scary scaly things and some big weepy moments. For me however, this episode was a big let down. Maybe Richard Wilson can make amends next week.