Doctor Who and the Armageddon Factor: Fourth Doctor NovelisationCompact Disc, 1 September 2019

Some time ago the White Guardian set the Doctor an urgent task to find and reassemble the six segments of the Key to Time. The Doctor and Romana arrive on the planet Atrios in the middle of an atomic war. There they must find the last, most vital piece of the Key--but sinister dangers await them. A novelization of a 1978 TV serial.