The Resistance kidnaps a Visitor doctor to tend to friendly alien Willie - but can the doctor be trusted? Robin discovers her new lover is an alien sent to impregnate her and create a second Starchild.

The former prison planet Varos, the future. The downtrodden population of miners are kept happy by real-life violence and murder broadcast live from the Punishment Dome. But then the TARDIS materialises inside the Dome...