The novelistation of the radio play 'Slipback' was written by Eric Saward.
Back Cover Blurb
The TADIS materialise on board the Vipod Mor, a galactic survey ship captained by the repulsive Orious Moston Slarn.
Things are not goin too well on board the spacecraft: a mysterious killer stalks the ship's infrastructure; a junior officer, whose body is four years older than his brain commands its bridge; the craft's computer seems to be developing its own distinctive personality; and Slarn threatens to vent his vindictive anger on his crew.
Soon the Doctor and Peri stumble upon a shocking secret, a secret upon which depends the fate of the entire Universe...