The first P.R.O.B.E. adventure sees former UNIT scientist Liz Shaw (Caroline John) dispatched by the Preternatural Research Bureau to investigate a series of bizarre murders. All of the killings have occurred near to a psychiatric hospital that is soon to close its doors. When wealthy industrialist Peter Russell (Colin Baker) suddenly and unexpectedly steps in to save the hospital from closure things get even more complicated for Liz. Are Dr Dove (Sylvester McCoy)the current director of the hospital and his aged predecessor Dr O'Kane (Jon Pertwee) hiding the killer somewhere in the hospital - and what is the secret of room zero?
P.R.O.B.E.: The Zero Imperative
Former UNIT scientist Liz Shaw investigates a series of bizarre murders near a soon-to-be closed psychiatric hospital. When the hospital is suddenly saved by a wealthy businessman events seem to run out of Liz's control.
