Human Nature

The name's Smith. John Smith.

Back in time again for the third adventure in this memorable season, and a quite-sublime opening instalment of Paul Cornell's two-part adaptation of his acclaimed Doctor Who novel, Human Nature.

Fom the very first explosive scene, this was an absolute treat and, if the concluding episode fulfills the promise on offer here, we could be hailing the finest Doctor Who story of the modern era.

Ironically, that grab-the-audience-by-the-throat opening scene - The Doctor and Martha rushing into the TARDIS pursued by an unfriendly laser beam - while typical of the super-high-octane nature of 2007 Who, was totally atypical of much of the rest of the episode. It was a gentler-paced tale than anything else since the series returned (although Martha kept up her running quotient!). But it was never slow - and totally gripping throughout.

Under threat of death from a race who want to absorb a Time Lord's life span to prolong their own existence, The Doctor could see only one escape route - changing his biological structure for a time until they lose his scent. Using the Chameleon Arch in the TARDIS for the first time, The Doctor became public schoolmaster John Smith in 1913 England, with no memory of who he really was - save for dreams in which he recalled some of his adventures.

Martha is also in 1913, and working undercover at the schoolhouse as a maid. Before undergoing his metamorphosis, The Doctor told her she must instruct him to open a fob watch, which will trigger his memories, and revive the Time Lord within him, if she senses danger, or when three months have elapsed.

Martha realises that the alien family have taken over the body of a maid with whom she had been working, but is horrified to find out the watch is missing - and she has no way of bringing back The Doctor. She's also dismayed to find out that John Smith has fallen in love with a human, the matron Joan.

Meanwhile, schoolboy Timothy Latimer, who pocketed Mr Smith's watch, opens the device, and his mind is filled with images of frightening future events. Another pupil, Jeremy Baines, has been taken aboard the spaceship of the alien family pursuing The Doctor, and his body has also been taken over, along with other members of the village, after being kidnapped by terrifying living scarecrows which are, in fact, soldiers for the aliens.

The possessed villagers track down The Doctor to the local dance and, despite his protestations that he doesn't know what they're talking about, they demand he changes back to a Time Lord - or they'll kill either Joan or Martha.

Even scribbling all that down has one nodding in satisfaction at a beautifully-structured episode, packed with interesting and well-realised ideas.

The living scarecrows were genuinely frightening. We have seen a scarecrow come to life in Doctor Who before, but that was one of The Master's umpteen "I am the master of disguises" in the classic series - The Mark Of The Rani, coincidentally set in a similar time period. The 2007 version - like all monsters in the new series, properly choreographed, were designed to lollop rather than gallop towards their victims, and this was an effective manoeuvre.

Talking of scary, there was a deliciously-malevolent performance from Harry Lloyd as the possessed Baines. Easy to take it into "ham" territory, but Lloyd pitched it right, with the "sniffing" out of his prey liable to send chills a-multiplying through many a viewer.

Almost a given that Jessica Hynes would be a delight as Joan, as she's a superb actress who never disappoints. And more good work from Freema Agyeman who had several interesting exchanges, touching on racism, sexism and classism, all prevalent in the early 20th century. Nothing too heavy, but nicely structured to make the viewer consider the issues.

Star of the show was the star of the show, though. Effectively playing another role - that of John Smith (and for which he was doubly credited) - David Tennant clearly relished the opportunity to show us his range. And, although he seeded in a few Tenth Doctorisms into Smith, this was a delightful and charming portrayal of a 1913 schoolmaster. Tennant's a high-quality operator, and his acting class shone through here, particularly in Smith's warm scenes with Hynes, and his bafflement at Martha's revelation that his dreams were reality.

The BBC are always terrific at period pieces - and really took us back into time with them. Having visited Shakespearean era and 40s New York as well this season, they've been busy bunnies. And Murray Gold proved he can do "restrained"!

I haven't read Cornell's book, but it will be fascinating to compare the original to the TV screenplay. Cornell's basic story is refreshingly different to anything seen in the rest of the series, and it's hard to pick faults with the script. So I won't. Great job.

Nice touch from Russell T Davies, too, naming Mr Smith's parents as Sydney and Verity - respectful acknowledgements to two key figures in the 1963 version of the show of which RTD is so fond, namely one of the programme's creators, Sydney Newman, and producer Verity Lambert.

Nine out of 10, and comfortably the best of an excellent season, which just keeps getting better.