An ancient evil approaches Earth bent on destruction and murder...but who is assisting it and who will stand in its way?
Former UNIT luminary Liz Shaw and her assistant Bayliss are investigating a series of bizarre murders, all committed near a soon-to-be-closed psychiatric hospital. When the hospital is unexpectedly reprieved by rich Industrialist Peter Russell events seem to move out of Liz's control. Are the incumbent director of the clinic, Doctor Dove and his predecessor Doctor O'Kane harboring the killer? What is the centuries-old horror hidden in the grounds? And what exactly is the secret of room zero?
Caroline JohnDr. Elizabeth Shaw
Jon PertweeDr. Jeremiah O'Kane
Sylvester McCoyDr. Colin Dove
Colin BakerPeter Russell
Mark GatissDr. William Bruffin
Louise JamesonPatricia Haggard
Sophie AldredPublic Relations Officer
Linda LusardiLouise BaylissDavid TerenceDaniel O'Kane / Eustace O'KaneNicola FulljamesDr. Beatrice HearstPatricia MerrickDr. Julie Gilchrist
Jonathan RigbyCummings
Alexander KirkOrderlyDaniel MillsGhostly Child Voice
Peter DavisonPatient One
