Andrew Robertson

Instead of landing on Calufrax as originally intended, they arrive on a different planet and encounter the Mentiads, and the strange Captain.

Still in search of the missing planet, Calufrax, the Doctor and Romana encounter the telepathic Mentiads and Zanak's ruler, the half man, half robot Captain.

The Doctor has discovered the sinister truth about Zanak and solved the mystery of the missing planet. On the Bridge, the Doctor meets the real ruler of Zanak.

Time is running out for the Doctor and Romana in their struggle to defeat the Captain. They join forces with the Mentiads to prevent the Captain and Xanxia from using Zanak to consume Earth.