Paris, 1920s. A casino glittering with bad intentions. A wedding night that ends with a severed head on the floor — and a room nobody entered, nobody left.
Detective Bencolin has seen a great deal. He has not seen this.
There is a madman somewhere in the crowd. A woman who knows more than she says. A Russian with a perfect alibi and a monocle that never fogs. And a murder so impossible that the only honest answer is: it didn't happen.
It happened.
Carr at his most wickedly theatrical — part locked-room puzzle, part Grand Guignol, entirely his own.