Now this is a tough one to review. I've just spoken to a friend who said he thought it was 'okay, but last week's was better'. He only came aboard for the new series, however.

'School Reunion' works on two very different levels. For new fans it's a nice piece set in a creepy school replete with aliens, a sinister headmaster, a talking robot dog and an old friend of the Doctor's who makes Rose think about where her relationship with him is going.

For those of us who have loved the show longer, it's all about Sarah Jane.

This is the kind of story which should have been done years ago - just what happens to a companion when the Doctor moves on. Sarah was a perfect choice because she was one of the few who didn't choose to leave. In many respects, she was the closest thing we had to a Rose before Rose came along.

Toby Whithouse's script is a masterclass in how to do several things at once within a short timeframe. We have the action, the sinister monsters, the character exchanges and too many standout scenes to count. Everything featuring the Doctor and Sarah is massively watchable, but other pieces like the Doctor and Finch's battle-of-words across the swimming pool and Finch's offer of everythung the Doctor could want are both wonderful.

After feeling a little unsure after New Earth I'm feeling once again the Saturday night joy I rediscovered last spring. This really is the best thing on TV right now and it's lovely to be able to say that about a show that I've cherished since I was very young, following the Doctor and Tegan, Peri and Ace (yes, I know I left out Mel - do you blame me?), and reliving the past adventures of the Doctor and a girl called Sarah Jane.

Next week, Steven Moffat returns to scripting duties (hurrah!) and we have Mickey along for the ride. Clockwork robots, spaceships, time portals ... with so many ideas, it's entirely possible a future Doctor twenty years from now could be bumping into a middle-aged, blonde woman called Rose, introducing her to his latest companion ...

В‘The Doctor meets Sarah-Jane Smith and K9 againВ’ When I first heard this simple premise regards I thought В“Oh God! They did really well with the last series and now they are going to try to top it by going overboardВ…ItВ’ll be a nightmareВ” I am DELIGHTED to say I was wrong!!!

Regards the actual story В– the Dr and company beat Aliens who are using children in a school as mini computers blah, blah, blah В– itВ’s unimportant because this adventure is about relationships; The Dr and Sarah-Jane, The Dr and Rose & Rose and Sarah-Jane. Not since last yearВ’s В‘FatherВ’s DayВ’ will you get a more emotional episode. I consider myself a regular beer guzzling, football loving bloke and yet I will freely admit to shedding a tear when the Doctor and Sarah-Jane said goodbyeВ…and then shedding another tear when the TARDIS dematerialised and you saw Sarah-JaneВ’s В‘presentВ’.

I wont ruin the story for those who have yet to see it, but I will merely tell you that for all the episodes that brought back old characters to face the new Doctor which lacked emotional impact and were humdrum, this is the episode to counteract them all!

The episode continues the new seriesВ’ ability to add humour to the series (Mickey realises heВ’s В‘the tin dogВ’, the teacherВ’s sleeping in the school, K9В’s one-liners and Anthony headВ’s glorious turn as the Headmaster), but this story had everything and also explains the DoctorВ’s reasons for not re-visiting old companions В– and itВ’s a good un!

My favourite creatures were always the Cybermen (I am possibly the only Who fan who hates Daleks) and I was a bit concerned about how they would be portrayed in the series future episodes, but if they show Cybermen the respect and class they have shown to the DoctorВ’s old-companions, I have nothing to worry about.

After being disappointed with New Earth & Tooth and Claw, this has renewed my faith in the series; Sarah-JaneВ’s face on seeing the TARDIS, meeting the Doctor again once she realises who he is and the final five emotional minutes of the episode are definite highpoints for all Dr Who fans!! Bring on the Cybermen!

This had to be the most eagerly awaited story of this season - even ahead of the return of the Cybermen. The only time in the history of Doctor Who that the Doctor has had the chance to properly say goodbye to a former companion. Let's look at the other aspects of the story first. The plot - well there had to be a reason for the reunion but for once the story takes second best to the character dialogue. It's a reasonable story, good aliens and special effects but nothing particularly new or clever. Anthony Head puts in the type of excellent performance you would expect and is a good foyle for DT's Doctor. Rose and Mickey do much to question their relationships with the Doctor and to ponder on their futures with him and of course the scenes between Rose and Sarah Jane Smith are what you would expect - mistrust, jealousy and grudging respect. Nice to see K9 back too even though his scenes were faiirly restricted - interesting that not only did he manage to get himself out of Sarah's car but he closed his own inspection panel too!!

But of course the main reason for this story was to reunite the Doctor with one of his best loved companions ever - journalist Sarah Jane Smith. Who cannot be amazed at how gorgeous Lis Sladen is - wow she is looking as good if not better than she did in the Pertwee and Baker years!! Her performance was absolutely first class and the continuity so well handled - particularly her remarks about the Tardis interior!!! For those doubting fans out there can there not at last be absolute proof that this new Doctor Who show is firmly established with the original???

And David Tennant excelled too - not quite sure what to do when he met Sarah after all the years - unable, at first, to explain why he "abandoned her" - we now find out it was indeed not East Croyden (as Sarah suspected at the end of the Hand of Fear) but Aberdeen!! The closing scenes showed just how much the Doctor really cared for Sarah - and Sarah in turn was able to accept his goodbye this time round - at last she (and her new K9) can start a proper life minus the Time Lord. However, even having gained some of Rose's respect, this is nearly blown when she supports Mickey's decision to join the Tardis crew!!

I suspect there were many tears shed in the closing scenes - this story equalled last season's "Father's Day" in the emotional stakes. What a corker of an episode that not only bridged the old and new Doctor Who but saw the reintroduction of a former colleague in a very clever and totally appropriate way.

Each episode of the new series adds further dimensions to the show and makes one wanting more. Well done all concerned for an extremely enjoyable 45 minutes!!!

This was an episode always destined to please the fans of the original series of Doctor Who and especially, of course, those who remembered the characters of Sarah Jane Smith and K9 with fondness.

The emotional centre of the story was that of the relationship between the Doctor and his two companions, the old and the new. And this was carried out extremely well, with all three actors excelling in their roles. The jealousy between Rose and Sarah was a little too immediate and obvious for me, but that is a minor niggle that may simply reflect the 45-minute episode format that is too short on time for more nuanced development. The scenes between Mr. Tennant and Ms. Sladen were the emotional highlights for sure - well, and the return of a K9 Mark IV at the very end!

It surprises me that so many reviews of this episode thus far have been quite so high in praise, however. A reviewer can only be expected to state their own personal view, but as one who was not around when Tom Baker was the Doctor, it strikes me that nostalgia has been allowed to compensate for an average plot. For the majority of viewers out there, the return of old characters is likely to be treated with indifference - Sarah Jane Smith is no more exciting as a one-off character than the Mox of Balhoon, and slightly less so than the enigmatic Face of Boe. I certainly do not begrudge longstanding fans an episode such as this - but I would disagree that this was superior to 'Tooth and Claw', and I think that the majority of the 8 million BBC viewers would concur even if the majority of readers of Outpost Gallifrey would not. It is just something to consider before being too harsh on Russell T. Davies on some of his stories: he tends to delegate the more interesting, adult stories to others, burdening himself with those that have to appeal to the widest audience.

Anyhow, back to 'School Reunion'!

The plot was reasonable, with good build-up. I liked the Krillitanes, although the idea of adding the biological and technological distinctiveness of other species to one's own has already been done somewhat by Star Trek's Borg. As has occasionally been the case with the new Who, the evil plan is a little generic and far-fetched - universe domination by breaking some secret enigma-like code we've never heard of before? I am not overwhelmed. For a 'good' episode, I am always happy to ignore such irksome details, but I do think that such flaws prevent an episode from being 'great'.

To conclude: good acting; a good central theme on emotions, relationships, and the character of the Doctor; an interesting alien; some witty dialogue and a reasonable plot. I thoroughly enjoyed this episode, just not as much as last week.

Oh, and to finish, Mr. Head did not disappoint at the Headmaster - excellent, excellent, job.

School Reunion was everything it promised to be and more. This was emotion on the scale of "Father's Day", a beautifully written episode, exploring the dynamics of what happens to the Doctor's companions after they have left. Sarah Jane was a perfect ex-companion with whom to explore this, as she was one of the most popular with fans, most dear to the Doctor, and one of the few who left the Tardis unwillingly, being unceremoniously shovelled out by Tom Bakers Doctor after he was called to his home world.

The Doctor looked absolutely cockahoop upon seeing Sarah Jane, and it was interesting and emotional to see Rose's reaction to the revelation that a time might come when the Doctor might have to leave her behind, to get on with normal life. The bitching between Rose and Sarah Jane about who had seen the biggest/greatest/most dangerous monsters and robots e.t.c. was hilarious, and probably totally what you could expect in a relationship triangle. The story could well have turned out to be a necessary add on, but in fact was a well thought out plot really. Anthony Stewart Head played the Headmaster quite convincingly, and I couldn't help thinking that if the "Master" was ever to return that Head would be brilliant for the role.

The Krilitanes were quite convincing, if slightly comicbook, but that is quite ok, ‘cos this is Doctor Who, and in Doctor Who anything is possible.

K9 is a character I have never known much about, as I stopped watching Doctor Who years ago when K9 was first introduced, thinking it to be a rather silly concept. However, I eat my words, because K9 here was so great, that I was shedding tears for him at the sacrifice scene in the school, in the same way that I did when Rose thought the Doctor had been eaten by the reapers in Father's Day; or the same way that I felt sorry for the dalek in Van-Statten's underground bunker last year. The effect of K9s demise on Sarah Jane was really heart tugging stuff.

The scenes inside and outside the Tardis at the end were sublime, the reaction of Sarah Jane on the "redecorated" Tardis, the conversation between Sarah Jane and Rose, the request that Mickey made to join the crew in order that he should cease to be their "tin dog", and the farewell hug at the end.

Then, as the Tardis dematerialises, a surprie for Sarah Jane, a perfect farewell present from the Doctor in the shape of a rebuilt - or mark four - K9. Oh and the kids were great too, especially Kenny, who became an unlikely hero to all his schoolmates for "blowing up the school". 10 out of 10.

Okay. I almost shed a manly tear; that was a beautiful and moving episode, with great bits of humour and drama added to the mix. Considering the episode was hyped mainly for the reunion between SJS and the Doctor, the villains and their motivations was brilliantly explored. And for anyone who really still doubts DT as the Doctor, just three words: The Pool Scene. The Doctor was at his best here; playful, powerful and quite prepared to tell an arrogant alien where to stick it. Even though ASH played it perfectly in that scene, the Doctor was actually more terrifying, especially when he said he used to have "so much mercy". You really are left with the impression that this is still as scarred a character as the Ninth Doctor was.

We also get more of an in-depth explanation as to why the Doctor really doesn't like to say goodbye to his travelling companions, why he tries not to form too much of an attachment to them. The loneliness and solitary nature of the Time Lord has been mentioned in passing before, but here it became a focus of the story, and David Tennant rose to the challenge. He seemed close to tears when he talked about how everyone around him would wither and die; interestingly, this is something he seems to be trying to break in his relationship with Rose. Equally interesting is the glimmer of dissatisfaction Rose seemed to hint at in her life with the Doctor, especially with Mickey joining the TARDIS crew.

And that ending..

Wow. I mean, wow. Perfectly played by David Tennant and Elisabeth Sladen, we get the Doctor finally saying goodbye to one of the show's most beloved companions, which allowed Sarah to move on with her life. With a robot dog in tow..

Yes, K9 was a great addition to the story, and the scenes with Mickey realising he was the human equivalent of a tin dog were brilliantly done.

Have to say, I'm somewhat less than impressed with Billie Piper for some reason. Maybe it was the way Rose and SJS spent a lot of their time sniping at each other; funny at first, but then slightly irritating. There's a part of me wishing that Sarah Jane had joined the Doctor. Or perhaps that's just nostalgia speaking!

Anthony Head was wonderfully creepy as the Headmaster (not the Master!), and his scene with David Tennant crackled with energy. It's a real shame that he probably won't be in the series again. If the role of the real Master were ever to crop up, he would have to be considered!

The CGI effects were not quite as good as Tooth and Claw's werewolf (what could be?), but they were still well done, aside from the slightly dodgy scene with Anthony Head on the roof opposite the cafe. Still, that's just one tiny complaint in what was a wonderful episode.The Krillitanes themselves were imaginatively designed (beating Star Trek's numerous bumpy headed aliens every time), with a clichéd idea given an interesting twist. Okay, they wanted to take over the universe, but using school children to solve an equation to give them control over time and space? Certainly different! Perhaps some of the plot didn't really make sense (why exactly did the school explode? Um, using earth school children to take over the universe?!), but who cares? It was fun!!

Amazing, moving, with a great story, imaginative alien creatures, a genuine sense of threat, and of course, the return of Sarah Jane Smith, School Reunion continues the superb run of Doctor Who 2006.