A British intelligence agent must track down a fellow spy suspected of being a double agent.
George Peppard
as John Shay
Joan Collins
as Sarah Booth
Judy Geeson
as Polly Bendel
Oskar Homolka
as Racovsky
Charles Gray
as Vaughan Jones
Nigel Patrick
as Colonel Scott
Keith Michell
as Adam Booth
George Baker
as Philip Crawford
Alexander Scourby
as Prof. Parker
Peter Bull
as Butterfield
Ernest Clark
as Roper
Peter Dyneley
as Balkov