The third season opens with a short TARDIS scene that neatly suggests that some time has passed for the Doctor, Vicki and Steven as well as for the audience. They all seem quite comfortable in each others’ company, and Vicki is even cutting Steven’s hair. While they initially think they might have landed somewhere peaceful where Steven can go for a swim, they’re quickly disabused of that notion by the arrival of a conical robot.

Just as she named Sandy the Sand Beast and Zombo the Zarbi, so Vicki names the robots Chumblies, and whereas Steven thinks they might be pretty vicious and the Doctor warns they might be killed, Vicki thinks they’re quite cute. It’s the first hint that this story is about not judging by appearances. The TARDIS crew are rescued from the Chumblies by the Drahvins, a race of artificially created warriors from the planet Drahva in Galaxy Four.

The Drahvins are all women, and they have funny eyebrows – the Doctor Who equivalent of Star Trek wrinkly foreheads. They warn of the Rills – ‘They are things. They Crawl. They murder.’ Vicki is immediately mistrustful, but the Doctor agrees to go with them back to their spacecraft.

Once there, the Drahvins introduce their leader, Maaga. She’s polite but cool, desperate to escape the unnamed planet before it explodes. Stephanie Bidmead is great – she has real authority, but doesn’t play Maaga as a one-note baddie. She gives a funny clap to wake up a run-down Drahvin, and later berates them with a note of desperation for losing a weapon to the Chumblies.

With most of the episode missing, the amount of random bleeping on the soundtrack suggests the production team were keen to make a lot of the Chumblies – the third type of gliding machine monsters after the Daleks and Mechonoids. From the section that does survive, the Chumblies seem functional, like a kind of blend of the Mechonoids’ multi-purpose tools and the general shape of the Daleks, with the added trick of being able to collapse into a shell like a robot tortoise.

Having showcased the Drahvins and Chumblies, dropped enough hints about the ‘revolting green monsters’ that are the Rills, and established that the planet has about a day left before it blows up, this is a pretty effective set-up. The regulars get an equitable chunk of the script to re-establish themselves after the summer break, with the Doctor sparring with Maaga, Steven fairly blasé, and Vicki insightful, brave and practical – volunteering to stay behind as a hostage while the Doctor and Steven go back to the TARDIS. This is a really solid opening episode.

Next episode: Trap of Steel

Four Hundred Dawns no longer exists. Not in any of its regenerations. This review is courtesy of the excellent Loose Cannon reconstruction