13 - Club of Masks by Allen Upward

Dive into the mysterious world of the Domino Club, where a case of opium poisoning is anything but simple. Following the murder of Dr. Weathered, our protagonist is plunged into a twisted game with stakes running high - a stolen case book that threatens the entirety of London society. Guided by Zenobia Salome, the Leopardess, and a poison unknown even to renowned expert Sir Frank Tarleton, the narrative unfolds through the eyes of an unwilling participant in this deadly charade. Unravel the mystery as we delve into the darkest corners of the human heart, exposing the dreadful lengths one might go to protect their secrets. This gripping detective story, with its unique psychoanalytical perspective, will keep you on the edge of your seat, challenging even the most seasoned mystery enthusiasts.