A number of leading Western scientists have been kidnapped only to reappear a fews days later. Unfortunately, each scientist has been brainwashed and is now completely useless. The British send their agent, Harry Palmer, to investigate. Palmer is surprised to be selected for such a mission (considering his past) and believes he has been chosen because he is expendable.
Michael Caine, Nigel Green, Guy Doleman, Sue Lloyd, Gordon Jackson, Aubrey Richards, Frank Gatliff, Thomas Baptiste, Oliver MacGreevy, Freda Bamford, Pauline Winter, Anthony Blackshaw, Barry Raymond, David Glover, Stanley Meadows