ISBN 0-00-616530-3 - Fontana, 1954
This Roderick Alleyn mystery takes place in post World War II France where in infamous team of Mr Oberon and Dr Baradi use a cult as a front for a heroin factory and distribution network. Their own perverse egos are fed by recruiting young women into the fold.
While still in London, Alleyn's wife Agatha Troy receives strange letters form a distant relative - P. E. Garbel who lives near the Chateau de la Chevre d'Argent where Oberon leads his cult. As the plot unravels, Alleyn employes the aid of Raoul Milano who helps bring things to an intense climax during a bizarre ritual.