The Invasion (Doctor Who) - Plot

Plot

The TARDIS evades a missile fired by a spaceship on the Moon, landing the Doctor, Jamie and Zoe in late twentieth-century England. The visual stabiliser has been damaged, rendering the TARDIS invisible, so they try to find Professor Edward Travers (of The Abominable Snowmen and The Web of Fear) to seek his assistance. They hitch a lift to London, and the lorry driver talks of International Electromatics, or I.E., the world's largest electronics manufacturer; but, after leaving them, the driver is promptly murdered by two guards from I.E. who have followed him by motorbike.

The Doctor discovers that Professor Travers has left for America with his daughter, leaving his London home in the care of Isobel Watkins and her scientist uncle, Professor Watkins, who has mysteriously disappeared while working for the same company, International Electromatics. The Doctor and Jamie go to IE's head office in London, to investigate. When the electronic receptionist refuses them entry, they seek out a back entrance, but are arrested and taken before IE's Managing Director, the sinister Tobias Vaughn, who gives them a cock-and-bull story of Professor Watkins being at a delicate stage of his work and refusing to see anyone. The Doctor is immediately suspicions, noticing that the inhuman Vaughn never blinks once during their meeting.

Vaughn persuades the Doctor to leave the damaged circuit from the TARDIS for testing. After they depart, Vaughn reveals an alien machine hidden behind a panel in his office wall, and learns from it that the Doctor has been recognised from Planet 14 (see Planet 14 Notes, below), and is a threat to their plans who must be destroyed.

The Doctor and Jamie are abducted by two strangers, and taken to a military transport aircraft housing a complete operations room, where they are reunited with Colonel Lethbridge-Stewart from The Web of Fear, now promoted to Brigadier, who is in charge of a military taskforce known as UNIT. He explains that he is investigating IE, because whenever people visit the IE offices they are strangely different afterwards. He also reveals that the lorry driver they met is a UNIT operative, and that he has disappeared.

Zoe and Isobel go to the IE building in search of the overdue Doctor and Jamie. They, too, encounter the computerised receptionist, but Zoe refuses to be fobbed-off by it, and she sabotages the machine. The alarm, which this triggers, results in their capture; Isobel is to be used as a hostage to force her uncle, who is being held captive, to co-operate with Vaughn.

Vaughn's chief scientist, Gregory, studies the TARDIS circuits and realises they are the product of an extraterrestrial civilisation. Vaughn thus realises the Doctor may have the knowledge which Professor Watkins lacks.

The Doctor and Jamie discover that Zoe and Isobel have fallen into Vaughn's hands. They return to IE, finding Zoe's feather boa among a consignment of packing cases being loaded onto a train, but are captured by the security chief, Packer. Vaughn denies kidnapping Zoe and Isobel, and suggests they meet the train on its arrival at the company's country compound. There they meet Professor Watkins, who shows the Doctor his invention, the cerebration mentor, a teaching device capable of inducing emotional changes. Vaughn eavesdrops on their conversation, hoping to learn more about the TARDIS and the Doctor.

The Doctor notices a deep space communications antenna in the compound. He and Jamie then quickly escape; and whilst hiding from the guards, Jamie sees a cocoon that appears to be breathing. Meanwhile, Vaughn confides in Packer that he intends to use the cerebration mentor to control their (as yet unnamed) allies, once the latter have invaded Earth. He also intends to use the TARDIS to get away, if the invasion fails.

Overhearing Packer ordering the guards to take Zoe and Isobel to the tenth floor, the Doctor and Jamie rescue them. The Doctor uses a radio transceiver given him by the Brigadier to obtain assistance from UNIT, who send a helicopter to airlift all four of them to freedom. Realising how dangerous UNIT are to his plans, Vaughn exercises hypnotic control over Major General Rutlidge, and orders him to cease UNIT's investigation.

The Doctor examines photographs of UFOs over the IE factory, and reasons that these are bringing the mysterious cocoons to Earth. He, along with Jamie, take a canoe and sneak up the canal into IE's London warehouse, where they witness a cocoon being brought to life by Gregory, and see a Cyberman emerge. They warn the Brigadier that a Cyber army lies hidden somewhere on Earth. But they are too late; Rutlidge has already shut down the UNIT investigation.

The Doctor suspects that the Cybermen are hidden in the sewers beneath the city. Vaughn tests Watkins' machine on an awakened Cyberman, driving the alien insane: it escapes into the sewers. Vaughn is satisfied. He now has a weapon he can use against the Cybermen, to maintain his control over them after the invasion. He arranges the invasion for dawn, when he will activate a mind-control weapon hidden inside every item of IE's consumer electronics all over the world.

The Doctor is desperately working on a device to block the cyber control signal. Isobel, Zoe and Jamie venture into the sewers to obtain proof of the Cybermen's presence on Earth, but stumble upon two Cybermen on guard. A UNIT squad attempting to reach them are killed. They become trapped between the two Cybermen and the insane one, until the latter, being irrational, attacks the other Cybermen: fresh UNIT troops wipe out the surviving Cybermen with hand grenades. But Isobel's photos of the Cybermen in the sewers are worthless, as the photographs look too much like fakes.

Watkins attempts to kill Vaughn, but learns to his horror that Vaughn has already been partially subjected to cyber-conversion, although he still has a human brain, and cannot now die from a mere bullet. UNIT frees Watkins from IE, while the Doctor perfects his depolariser, which protects the wearer against the Cyber control signal. The spaceship on the Moon (which fired the missile at the TARDIS) will send the hypnotic signal, and the Cyber invasion fleet will home in on the transmitter at the IE factory.

The Brigadier orders all his troops to be fitted with a depolariser on the back of the neck. At dawn, the signal is broadcast, causing the collapse of the human race, and hundreds of Cybermen emerge from the sewers of London.

UNIT intend to deploy a Russian missile to destroy the source of the signal, while using UK anti-missile-missiles to destroy the incoming Cyberfleet. Captain Turner is sent to Russia to organise this, while the Brigadier goes to the RAF's Henlow Downs missile base. There aren't enough missiles to hit all the ships, and the base computer is too slow to calculate a workable solution; but Zoe exercises her talents as a mathematical genius, calculating a pattern, which can cause a chain reaction of explosions.

The Doctor tries to dissuade Vaughn. The missiles are successful, thanks to Zoe's calculations, and the entire cyber-fleet is obliterated. The Cybermen blame Vaughn for this setback, and announce they will use a Cyber megatron bomb to destroy all life on the Earth. The Doctor persuades Vaughn to aid humanity, and they take a helicopter to the IE factory to shut off the radio beam so it cannot guide the incoming bomb.

As they make their way towards the transmitter, Vaughn meets his end when his former allies gun him down, but the homing signal is successfully shut off with the help of some UNIT soldiers. The megatron bomb is destroyed by an anti-missile-missile, while the Russian rocket destroys the Cybership broadcasting the hypnotic control signal, which had been forced to come in close to the Earth before launching the bomb, as it no longer had the signal of Vaughn's transmitter to aim at.