Spotty espionage film directed by Siegel stars Caine as a secret agent whose investigation of an international smuggling ring is complicated when his son is kidnaped. Although Vernon and Seyrig play key roles in the kidnaping--the ransom being a fortune in diamonds that are in Caine's
possession--suspicion is placed on Caine himself by his superior Pleasance. The whole situation is put under the magnifying glass by Scotland Yard investigator Revill, who does not proceed without a bit of dry humor. The good opening half of the film gives way, during some lengthy voice-over
exposition, to a bogged-down latter half, and eventually the film plods on to a less-than-sati...