A group of scientists are kidnapped and taken to an outer space outpost in order to save Earth from destruction.

Scientist Doctor Who accidentally activates his new invention, the Tardis, a time machine disguised as a police telephone box. Who, his two granddaughters Barbara and Susan, and Barbara's boyfriend Ian are transported through time and space to the planet Skaro, where a peaceful race of Thals are under threat of nuclear attack from the planet's other inhabitants: the robotic mutant Daleks.

The TARDIS brings the Doctor, Susan, Barbara, and Ian to the planet Skaro where they meet two indigenous races — the Daleks, malicious mutant creatures encased in armoured travel machines, and the Thals, beautiful humanoids with pacifist principles. They convince the Thals of the need to fight for their own survival.

The Doctor and his companions are pursued through time and space by the Daleks on the desert planet Aridius and beyond.

The TARDIS arrives in a desolate future London, where the Doctor discovers his old enemies the Daleks have taken control of Earth.

On the planet Vortis, the Doctor and his companions aid the butterfly-like Menoptra in their battle against the parasitic Animus and its mind-controlled minions, the ant-like Zarbi.

The Daleks draft the Second Doctor into distilling the Human Factor. Once implanted, it will make the Dalek race invincible. Jamie's faith in the Doctor is stretched to the limit as the Doctor appears to be collaborating with the Daleks. The Doctor has a few tricks up his sleeve, but then again so might the Daleks.

In the year 4000, the Daleks conspire to conquer the Solar System. Their scheme involves treachery at the highest levels and a weapon capable of destroying the very fabric of time. Only the Doctor and his friends can prevent catastrophe — and there is no guarantee they will escape with their lives...

When the Second Doctor, Polly, Ben and Jamie visit a human colony that appears to be one big holiday camp, they think they have come across a truly happy place. Yet a shadowy presence soon makes them realise that the surface contentment is carefully controlled.

A look at the making of the Doctor Who story 'The Dalek Invasion of Earth' (1964)