PROBE: The Zero Imperative

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?

Cast

Caroline John

Jon Pertwee

Sylvester McCoy

Colin Baker

Mark Gatiss

Louise Jameson

Sophie Aldred

Linda Lusardi

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David Terence

?

Nicola Fulljames

?

Patricia Merrick

Jonathan Rigby