The Magellanic Clouds, the planet Ribos, an unknown time. Ordered by the White Guardian to collect the pieces of the omnipotent Key to Time, The Doctor, K-9 and his new assistant Romana arrive. Collecting the first segment is not going to be easy…

Cyril Luckham, Iain Cuthbertson, John Harmill, Nigel Plaskitt, Oliver Maguire, Paul Seed, Robert Keegan