The TARDIS materializes on a spaceship. The Doctor and Jamie are attacked by a Servo Robot and Jamie manages to contact a nearby space station. They are rescued but the ship they are on also sends some Cybermats out that also enters the station. These are they used to begin the invasion of the space station by the Cybermen. They mean to use it in their attack on Earth.
Jamie and one of the sation's inhabitant, Zoe Heriot, go to the ship to get equipment from the TARDIS's. The Doctor also frees the space station's crew from the hypnotic control of the Cybermen. He also destroys all the Cybermen on the station. With the TARDIS equipment and the station's x-ray laser, they destroy the approaching Cybermen's spacecraft.