After the owner of a shabby London detective-bureau commits suicide, Cordelia Graytakes over the shop without hesitation. Her first case concerns the obvouisly unnatural death of a young student, son of wealthy James Callender. Her determination to find out what kind of person this student might have been grows into an obsession and gets her tangled up in a net of intrigues and obsessions. Young Mark Callender had hanged himself in the course of a somewhat unusual sexual experiment, something that might be explained out of the context of his family. After all, the mother seems, although dead for some time, still mysteriously present, and the father radiates irritation and threat …