A government team researching cures for plague find their results put on the Official Secrets list. One of their number is so incensed by this that he lets the maimed and jealous companion of a female colleague draw him into what, technically, could be a treasonable act.
Tony Britton
as Dr. Robert Marriott
Virginia Maskell
as Dr. Lucy Byrne
Ian Bannen
as Alan Andrews
Kenneth Griffith
as Dr Shole
Peter Cushing
as Professor Sewell
Thorley Walters
as Special Agent Prince
Donald Pleasence
as Parsons, alias Bill Brown
Spike Milligan
as Arthur, lab orderly
Raymond Huntley
as Sir George Gatting the Minister of Defense
Sam Kydd
as Slater
Anthony Booth
as Parkin
Basil Dignam
as Dr Childs