France 1934. On a coastal island the Provincial Police arrest the senior prosecutor in the Ministry of Justice for the murder of his mistress. Chief Inspector Gambrelli, of the Metropolitan Police, is dispatched from the City to review the case and report his findings to the Ministry. Suffering the heat and humidity of the island Gambrelli begins his inquiry asking more questions than the local authorities can answer. He leaves the sun bleached, sandy streets of the island and returns to the grand boulevards and cobblestone alleyways of the City. Methodically the Chief Inspector probes the lives of the prosecutor, his wife, and his mistress. Simultaneously detectives search for the murdered woman's younger sister, fearing she may become the killer's next victim. Following a twisting path of love, betrayal, greed, and violence Gambrelli searches for the motive that led a killer to a young woman's door.