The one where he actually is "Doctor Who".
The TARDIS arrives in contemporary London, and the Doctor and Dodo visit the Post Office Tower, where they meet Professor Brett and his new super-computer WOTAN, which can think for itself and is about to be plugged into a worldwide computer network.
WOTAN decides that machines are superior and should rule the world, and hypnotises humans into building the titular War Machines, which turn out to be more than a match for the army. The Doctor uses a magnetic field to capture one, which he then reprograms to destroy WOTAN.
Dodo, having been hypnotised by WOTAN, decides she's had enough adventure. Since she's back in her own time, she decides to stay there. In one of the lamest departure sequences for any companion, she isn't seen after episode two and says goodbye to the Doctor in episode four via a note, delivered by Polly. The Doctor leaves, but not before Professor Brett's secretary Polly and able seaman Ben Jackson enter the TARDIS while trying to return a missing TARDIS key to the Doctor.
- A.I.-cronym: WOTAN, from Will Operating Thought ANalogue, referring to its purpose as an abstract experiment in AI.
- A.I. Is a Crapshoot: There's no actual explanation of why WOTAN turned out to be power-hungry and malevolent.
- Bring News Back: Ben escapes to tell the Doctor and others what WOTAN does.
- Celebrity Resemblance: When the Doctor arrives at the Inferno club, Polly comments that he "looks a bit like that disc jockey". Presumably she means Jimmy Savile, which makes it a somewhat unfortunate comment now...
- Character as Himself: For the first three episodes, WOTAN is listed last under the cast as a cast member playing 'himself'.
- Complaining About Rescues They Don't Like: Ben tells a man to stop hassling Polly, he starts a fist fight with Ben, and Polly complains — though Dodo intervenes on his behalf.
- Though to be fair, he did tell her "be careful who you encourage" - implying it was her own fault she was harassed by that fellow.
- Computer Equals Tape Drive: Not only WOTAN but the War Machines have these — the latter are mounted on the outside where they can easily be damaged by gunfire!
- Justified in that the story was set in 1966.
- Damsel in Distress: Mind control effects on two women. (Plus the man who wouldn't leave Polly alone at the nightclub.)
- Disposable Vagrant: A bum tries to sleep in an abandoned building, unaware that WOTAN is using it to construct one war machine.
- Distressed Dude: Most of the mind control victims are men. And Ben gets captured and forced to work without it.
- Dropped a Bridge on Her: Dodo.
- The Dulcinea Effect: Ben fights for Polly rather quickly.
- Establishing Character Moment: Polly is introduced privately pulling a silly face to make fun of her nagging sexist boss, and quickly turning it into a forced smile before looking around. Ben is introduced moping in a bar, beating up a man who sexually harasses Polly, and then blaming Polly for the assault.
- Five Rounds Rapid
- For Happiness: The bartender asks Polly to help cheer up Ben. Polly comments on how reliably she is called on for such measures.
- A Friend in Need: Ben is first persuaded to act when he sees Polly being hassled at the nightclub.
- Hypno Pendulum: This is how the Doctor mesmerises Dodo, only instead of using a pendulum he swings his hand with the ring on it back and forth in a similar motion.
- Idiot Ball: Plenty from WOTAN — its hypnotised slaves work like machines until they drop (WOTAN should know that the inefficient humans require regular food and rest) and it tries to take over London by brute military force instead of using its role as an advisor to the government to manipulate events.
- In Harm's Way: Ben is morose because he's on shore duty.
- Landmarking the Hidden Base: The Post Office Tower serves as the villains' HQ.
- Master Computer: WOTAN, which is similar to Skynet but, this being The '60s, it consists of a single Master Computer based in the Post Office Tower in London.
- Mind Rape: Dodo gets hypnotised by WOTAN, necessitating the First Doctor to hypnotise her back to normal. Since Dodo quits afterwards, only giving a second-hand goodbye through Ben and Polly, some fans speculate (especially in light of the scene that went on between the Tenth Doctor and Donna) that the Doctor actually wiped her memory, or else influenced her to leave for her own perceived safety.
- Newscaster Cameo: Real-life newsreader Kenneth Kendall plays himself in news reports about the War Machines.
- The Power of Friendship: The mind-controlled Polly clearly sees Ben escaping, and says nothing. When someone asks after him, she explains, but when he asks her why, she does not know, and after a moment, starts to remember that he had been her friend.
- Put on a Bus: Once Dodo is freed from WOTAN's influence, she's removed from the plot. In the second episode. And in the most perfunctory way possible: the camera just pans right off her onto the Doctor in mid-scene, and she's never seen again; her decision not to return is briefly described second-hand several episodes later.
- Real Life Writes the Plot: Midway through production, Jackie Lane's contract expired, hence Dodo's sudden departure.
- Ripped from the Headlines: The story focuses on the newly-built and cutting-edge technology of the Post Office Tower, as well as theoretical new concepts like computers all over the world linked together via telephone lines (which of course is presented as the computer ringing people up to talk to them with words).
- The '60s: Remember when that computer took over the world?
- Stay in the Kitchen: Polly is constantly told to stay out of the computer science and go and make coffee.
- Tin-Can Robot/Killer Robot: The War Machines.
- Worst News Judgement Ever: The death of a tramp makes the front page of The Times. Actual deaths in 1966 included writers Evelyn Waugh and CS Forester, actors Buster Keaton and Montgomery Clift, comedian Lenny Bruce and Captain Cook's 200 year-old tortoise. Their deaths did not make the front page of The Times.
- You Have Failed Me
- You Shall Not Pass!: Episode 3 ends with a war machine bearing down on the army and random civilian director-type-people. They all turn and run for cover, but the Doctor stands his ground.