In the Cold War era, a Russian spy and his boyhood friend decide to defect to the West by crossing the North Sea to Yorkshire, where their protagonist, Walter Searby, is charged with discovering what lies behind three bodies found on the beach in the same area. Searby is worried about possible infiltration of SIS. He recruits his own spies from guests at a small hotel, a one-time Jewish cockney petty-crook, an ex-colonial police inspector and a widowed author of soft pornography, who develops a crush for the master spy. In liaison with the local police force, which is prepared to turn a blind eye to his methods, the mystery of the three bodies is solved and the landing of iron curtain agents brought to an end.