A 1960's Crime/Drama filmed at Pinewood Studios and on location in London. The story concerns the somewhat uneasy relationship between a Scotland Yard Detective, Johnoe (Nigel Patrick) and the Squad Chief, Bestwick (Harry Andrews) over the use of paid informants. Despite orders not to use informants and to adopt more scientific principals of detection, Johnoe continues on until one of his informants is murdered. Immediately he finds himself in a frame for corruption and with few friends left on his own side of the law his only option is to enlist the help of the murdered man's brother (Colin Blakely).