1863. Superintendent Henry Jarrett, formerly of the Hong Kong police and now Chief of the Detective Department at Glasgow Central, is comfortably ensconced in Elsie Maitland's superior guest house for single gentlemen. Unfortunately, this tranquillity is short-lived and problems start to come thick and fast. First, a major bank robbery calls for the best efforts of Jarrett, Inspector Charlie Grant and Sergeant Tommy Quinn. Undermanned and under-funded, the department soon has to deal with a series of gory murders, an attacker who lies in wait for maids on their night off, and a cold-blooded poisoner. Stretched to breaking point, they can well do without the activities of a confidence trickster and his loyal assistant.