The novel centers on the residents of a single street of a small English town; mistrust and suspicion grow when a series of strange warnings are received by the residents. The messages of death escalate into a number of dangerous pranks, and Desmond Merrion, friend of one of the victims, is asked to investigate. Following the deaths of a couple in one of the street's houses, Merrion's long-time associate, Inspector Arnold of Scotland Yard is also called in to solve the mystery and catch the killer.