42

The midway point of Series 3 sees The Doctor and Martha return to the future for a real-time (give or take a few minutes) adventure set on a spaceship in a similar futuristic era to last season's excellent The Impossible Planet/The Satan Pit.

This was, in effect, Martha's first trip as an "official" companion, and she's afforded the kudos of some Doctorly "jiggery pokery" to her mobile to enable her to call home in the pre-credits scenes in the TARDIS - which is to prove highly significant later in the episode (and, indeed, with respect to happenings later in the series).

The TARDIS answers a distress call from a cargo ship 42 minutes (hence the episode title) from being engulfed by a sun after suffering engine failure. Quickly separated from the TARDIS, which is trapped in a superheated hold, The Doctor and Martha find themselves in the same race against time for survival as the crew, headed by Kath McDonnell.

While Martha goes off to assist crew member Riley battle through a series of puzzles to open the ship doors leading to the auxiliary engines, which will be required to power the ship away from the sun, The Doctor is called upon to investigate the mystery of why McDonnell's husband, Korwin, has been possessed, and is vapourising the rest of the crew, one by one.

Martha and Riley are cast adrift in an escape pod by Korwin, but The Doctor risks his life by climbing outside the spaceship to restore the magnetic field which pulls the pod back. In doing so, The Doctor gazes into the sun, and discovers that it is a living organism and McDonnell has scooped out its heart for fuel.

Now possessed himself, The Doctor fears he will kill Martha and the rest of the crew unless the burning sun inside him is frozen out and the stolen solar particles restored back to the sun - but Korwin turns off the freezing chamber.

Shocked by the results of what she has done, McDonnell lures her possessed husband away, and propels both of them to their death out of an airlock, to buy the others some time. With The Doctor incapacitated, it is left to Martha to inform the surviving crew members to jettison the fuel back to the sun, and they reach the auxiliary engines in time to avert flying into the sun.

The Doctor is "dispossessed" and rewards Martha for saving his life by presenting her with the TARDIS key. Meanwhile, back on Earth, Martha's mother, worried about her daughter's involvement with The Doctor, is having Martha's calls home monitored by a mysterious black-suited woman . . .

This was effectively a mini space movie truncated into a 45-minute TV programme. Impossible to pull off. But they did it. Terrific efforts - even by the magnificently-high standards this production team have set - from all departments.

Firstly, it was an excellent Doctor Who scripting debut from Chris Chibnall. As Torchwood's head writer, Chibnall is well versed in what Doctor Who's head writer, Russell T Davies, requires, and is seen seen as a safe pair of hands.

Chibnall's script rattled along at an electrifying pace, and it was beautifully complemented by Martha's "phone homes" to her mum. In 42 (obviously a play on 24, and a great title), this served as a breather for the viewer from the action and it was a fascinating diversion, from a character point of view, to explore the mother/daughter dynamic right in the heat of a life-or-death struggle. And calling your mum from a spaceship to find out whether Elvis or The Beatles had more number ones is pure Doctor Who gold!

From a series point of view, advancing the "Saxon arc" by having Martha's calls monitored by a "sinister woman", as the credits brilliantly described her, was an added bonus for viewers.

The direction, from the Doctor Who legend Graeme Harper, was top drawer, as you would expect. This one had the air of the classic amongst classics, Caves Of Androzani, and was full of energy. As, to be fair, most DW stories are. But 42 started in top gear and pretty much maintained the level. I loved the lighting here - very different from the bright white sets of spaceships and stations in the future during the classic series. However, the movie-style darker, smoke-filled sets depicted, as in Gridlock, a brave new world which isn't all high-tech and shiny droids. In fact, it's all falling apart! Bit like nowadays . . .

I also adored Murray Gold's score here - it built and built and built, and accentuated the action perfectly. Super moment, too, when the music dropped all together when The Doctor watched Martha drift away in the pod, and mouthed, "I'll save you."

More fabulous work from The Mill, too. Another great spaceship, and their sun was reminiscent of their Impossible Planet black hole, but none the less effective.

Excellent performances from the guest cast, notably Michelle Collins as doomed Captain McDonnell. No camping it up whatsoever, and treating the material seriously paid dividends. Collins and Anthony Flanagan (Scannell) are both lead actors, so further evidence of Doctor Who's pulling powers that such big names are on board. Some good moments between Riley (William Ash) and Martha, too, when they thought their death was imminent.

Great script for Freema Agyeman as Martha, with plenty of action and getting to save the day (dare I say it, Rose-style). And she got the key to the door! But Freema's been great since Day One, and there's no sign of a drop-off in the quality nor enthusiasm she brings to the part. And the character is a massive part of the series.

There was a fascinating - and unexpected - twist to The Doctor's character. It's very rare that we see him a) scared and b) actually admitting he's scared, both of which happened here after his possession. Christopher Eccleston's Doctor certainly displayed real terror when encountering the Dalek in Utah, but this was the most afraid David Tennant's incarnation has ever been.

Clearly, this possession had a profound effect on The Doctor - as underlined by his not joining in with the "traditional" end-of-adventure jolity with Martha. But will this experience prove significant later in the series, perhaps even in the next episode?

Eight and a half out of 10, and the pick of the series so far.