While the Doctor is horrified to learn the full extent of the side-effects brought into being by Roley's research, Sam heads off to experience the swinging London of her parents' youth. Instead she experiences deadly danger at the hands of a sinister half-man half-robot double act whose agenda is inextricably linked to Roley's test subjects.

The Doctor has stumbled upon the reawakening of a computerised alien survival programme hidden in the brains of these afflicted people. Tainted with their madness, its new function could destroy all life on Earth...

This is another book in the series of adventures featuring the Eighth Doctor and Sam.