The Rock of Judgement. Court, prison and place of execution for the Uva Beta Uva system, hewn into the skin of a rocket-powered asteroid. Not a good place to be. Particularly not for two Time Lords and their dog.

Upon arrival on the Rock, the Doctor, Romana and K9 find themselves embroiled in the plans of a maverick law-man, but that is just the beginning of their troubles. A highly-strung artist's gallery holds a deadly secret... and soon everyone's lives will be in danger.

They struggle to know who's good and who's bad, a terrible scheme is being unleashed. With enemies old and new attacking both sides, can they possible escape alive?