With the entire world unconscious apart from the Doctor and his friends, the Cybermen are poised to invade and only Zoe, the Brigadier and a missile crew can stop them.

The TARDIS lands on the planet of the Gonds, a primitive and enslaved people. Every year, two of the finest Gond students are sent to be 'companions' of the mysterious and unseen Krotons. But the Doctor reveals that only death awaits them.