Very much in the vein of Carol Reed's similar cold war thriller "The Third Man" (1949), this is a gritty and characterful story set in Berlin just before the Soviet Union imposed travel restrictions. This time, the Communists kidnap "Susanne" (Claire Bloom) - she happens to be the sister of British officer "Martin" (Geoffrey Toone) and we are now presented with an intriguing and internecine series of spy and counter-spy scenarios that revolve around the dubious "Ivo" (James Mason) with whom the missing woman had been associating with - and has fallen for. It transpires that she is being held…