In this first sequel to The Ipcress File (1965), British spy Harry Palmer (Michael Caine) is sent to West Berlin, where British intelligence has word that a senior Russian officer, Colonel Stok (Oskar Homolka) wants to defect. Palmer arranges to meet Stok over the border in East Berlin, where the Russian tells him that he wants to be spirited to the West by the same organisation that has arranged a series of daring escapes from East Germany, and to be settled in a new life in Britain. Palmer is suspicious of Stok's motives and sceptical of his claims that he wants to defect. However, Palmer's boss, Colonel Ross (Guy Doleman), orders him to arrange the defection. The plan sees Palmer reunited with an old friend, Johnny Vulkan (Paul Hubschmid), now working for the British in Berlin, and become involved with a beautiful female spy, Samantha Steel (Eva Renzi).