The Time Lords have a mission for the Doctor. Together with Sarah and Harry, he finds himself stranded on the war-torn planet Skaro where the conflict between the Thals and the Kaleds has been raging for a thousand years. Chemical and biological weapons have started a cycle of mutation among the planets inhabitants that cannot be stopped. But Kaled scientist Davros has perfected a life support system and travel machine for the creature he knows his race will ultimately evolve into the Dalek.

The Doctor must stop the creation of the Daleks, or perhaps affect their development so they evolve into less aggressive creatures. But with Davross plans to destroy the Thals and to wipe out any dissenters among his own ranks in progress, is the Doctor already too late?

This novel is based on a Doctor Who story which was originally broadcast from 8 March12 April 1975.

Featuring the Fourth Doctor as played by Tom Baker with his companions Sarah Jane Smith and Harry Sullivan

Terrance Dicksworked on scripts forThe Avengersas well as other series before becoming Assistant, and later full Script Editor ofDoctor Whofrom 1968. Dicks worked on the entirety of the Jon Pertwee Third Doctor era of the programme, and returned as a writer - scripting Tom Baker's first story as the Fourth Doctor: 'Robot'. His later script writing credits onDoctor Whoincluded the 20th anniversary story 'The Five Doctors'. Terrance Dicks novelised many of the originalDoctor Whostories for Target books, and has written originalDoctor Whonovels for BBC Books.