It's the middle of a hot, dusty St Petersburg summer in the late 1860s. A doctor's wife and son die suddenly and the doctor is arrested, suspected of poisoning. But when further, apparently unconnected, murders occur, Porfiry Petrovich is forced to reassess his assumptions. Delving into the hidden, squalid heart of the city, he is brought face to face with incomprehensible horror and cruelty, in this vivid rendering of a brutal and stifling nineteenth-century St Petersburg.