To the well-known private detective Stas Severin, addressed by the daughter of a man who was cruelly killed by a sexual maniac. The serial killer, nicknamed the Lady Blank, has been operating in the city for a month and a half already. Her sadly famous “calling card” is a lone playing card found in the bloody body of the victim. Who is she, and how does she manage to slip past the police? To begin with, Stas decides to get acquainted with the victim’s circle—and is met with a shocking discovery: almost everyone he comes across is a work-in-progress for a lunatic asylum. But it seems that even the psychiatrist doctor of this strange family is hiding something very important…