Although Doctor Who has been serialised since the beginning, the last few episodes have really pushed the idea that this is a continuing adventure. Mission to the Unknown established the Dalek threat to invade the Solar System. Then the previous week had Steven stabbed and Katarina stumble on board the TARDIS. The Nightmare Begins follows on from both these events.

It does this in quite a neat way. Following on from the end of Horse of Destruction, the opening scene has the Doctor and Katarina fretting over a shirtless Steven’s septic shock (the recovered episode leaves us wondering which of them undressed him from his Trojan outfit and put him into his natty slacks) and deciding that the TARDIS needs to land somewhere. By a remarkable coincidence, that’s on the very planet Vicki pointed out on the monitor six weeks ago, in The Exploding Planet. And then, in a neat call-back to that episode scene two cuts to Bret Vyon and Kurt Gantry, basically on the same sets doing exactly what we last saw Marc Cory and Gordon Lowery doing: fleeing through a jungle, trying to get a message to Earth. The two scenes therefore link together events from the last six episodes and launch this epic story in a suitably dynamic way, one that makes it feel climactic even from the outset

The third scene is then tonally very like what we’ve just been watching in The Myth Makers – that is, characters behaving anachronistically. Whereas in The Myth Makers it was seeing the Greek heroes talking like they were everyday folk in 1965. Here it’s seeing two people in a futuristic control room doing mundane office jobs and chatting about galactic politicians and space cars just like 1960s workers. It’s a great way to introduce Mavic Chen, the Guardian of the Solar System – being interviewed as he heads off on holiday in ‘my Spar’ and talking in the same empty platitudes as contemporary politicians. In fact, in language so thoroughly meaningless and vague that it becomes as hilariously pointed as a Jim Hacker speech:

It is my earnest hope that the solar system may continue along this path of peace, this path that was laid by the signing of the non-aggression pact of 3975. Now, in this year of 4000, we can feel justly proud of that pact. May the past 25 years prove that they are the dawn of an everlasting peace which will spread throughout the universe. Let us go forward together, secure in the knowledge that the life ahead is built on the cornerstone of richer understanding, not only of the past or of the present, but also of the future. And may it be this cornerstone, so firmly laid, be built upon in brotherhood and bring peace, progress and prosperity to each and every one of us.

No wonder Roald, who has been silently mouthing along to Chen’s platitudes, comments, ‘It’s nice to hear his speech again.’

We then swap back to Kembel, and a scene that evokes the moment when Lowery begged Cory to kill him. However, though he’s hard bitten, Vyon doesn’t seem as coldly callous as Cory, and Courtney does a great job of playing him as a man on the edge, ever watchful and twitchy with nerves. He reluctantly leaves his injured friend to try to complete the mission. Kurt is then killed by a pursuing Dalek which looms over him, impassively gunning him down. It’s a good example of Douglas Camfield finding interesting ways to film the Daleks, menacing, bristling with fury.

Vyon then encounters the Doctor, steals the TARDIS key at gunpoint, and forces his way into the Ship. We haven’t seen anything like it since Ian and Barbara forced their way aboard – the TARDIS has previously been otherwise inviolable. Even the Sensorites only managed to steal the exterior lock. So to have a character invade its safety is genuinely shocking. Fortunately, Steven bashes Vyon over the head and when he comes to he’s held, rather implausibly, in the Doctor’s previously unseen “magnetic chair”.

The Doctor goes to investigate the nearby city, and discovers first Cory’s skeleton and tape, then the Daleks, and then learns Mavic Chen is in league with them. And after this triple whammy of revelations, he makes his way back to the TARDIS only to find the door open, and the Daleks surrounding it. Given only minutes earlier Bret got inside, this suggests that the Daleks won’t be far behind. It’s a genuinely suspenseful ending to an episode that’s funny, scary and dangerous.

Next episode: Day of Armageddon