The TARDIS arrives on Earth in the middle of a meteorite shower and the Doctor is found by UNIT troops and taken to a nearby hospital. The Brigadier is faced with having to cope not only with the mysterious meteorites but also with Ransome, an ex-employee of a local plastics factory, who claims he has seen a walking mannequin. The meteorites turn out to be hollow globes containing the Nestene consciousness, a disembodied alien intelligence with an affinity for plastic. A Nestene agent, Channing, has infiltrated the plastics factory and is using energy from the globes to animate Autons - mannequin-like figures and realistic replicas of senior establishment figures - with the aim of colonising the Earth. Aided by newly-recruited UNIT scientist Dr Elizabeth Shaw, the Doctor thwarts this scheme by repelling the Nestene consciousness into space and thereby neutralising the Autons and the monstrous tentacled form that it has been creating for itself in a tank within the factory. Channing, revealed to be no more than a sophisticated Auton, is likewise deactivated.

维基：

维基：

The Doctor is an observer and UNIT are providing security cover at an experimental drilling project designed to penetrate the Earth's crust and release a previously-untapped source of energy, named Stahlman's Gas after its discoverer. Professor Stahlman dismisses the concerns of the project's Executive Director Sir Keith Gold and exceeds all safety margins in order to expedite the work. Soon however the drill head starts to leak an oily green liquid that transforms those who touch it into vicious primeval creatures with a craving for heat. The Doctor is accidentally transported by the partially-repaired TARDIS control console into a parallel universe where England is ruled by a military dictatorship. The drilling project is at a more advanced stage here and, thwarted by his friends' ruthless alter egos, he is unable to prevent the penetration of the Earth's crust, which ultimately causes the planet's destruction. Escaping back to his own universe, where the drilling is still in progress, the Doctor tries to warn of impending disaster. At first he is disbelieved, but his words are borne out when the power-crazed Stahlman is himself transformed into one of the hideous primordial creatures. The Doctor, aided by consultant Greg Sutton, kills Stahlman with ice-cold blasts from fire extinguishers. He is finally able to shut down the drilling with only moments to spare.

The Master arrives on Earth at a circus run by a man named Rossini and steals a dormant Nestene energy unit from a museum. He reactivates it using a radio telescope and uses his hypnotic abilities to take control of a small plastics firm run by the Farrel family, where he organises the production of deadly Auton dolls, chairs and daffodils. Humanoid Auton dummies distribute the daffodils - designed to spray a suffocating plastic film over their victim's mouth and nose - by giving them away free to members of the public in a fake promotional campaign. The Master plans to activate the flowers with a signal from the radio telescope, which he will then use to bring the main Nestene Consciousness to Earth. The Doctor manages to persuade the Master that the Nestenes will have no further use for him once they arrive. The two Time Lords then work together to send the Consciousness back into space.

维基：

维基：

The making of Doctor Who: Spearhead From Space Episode 1 (1970), an iconic serial which relaunched Doctor Who (1963) as a colour series and introduced Jon Pertwee as the Third Doctor.