It had been so quickly done that he felt almost as if a little knife had actually flashed by him and stuck, quivering, in the door at his back.

Violet Hunter disappears at dusk one evening on a lonely road not far from a mysterious sanatorium. Her body is found buried in her friend’s garden. Has Linda strangled her in a fit of jealousy? Or has the sanatorium’s sinister foreign doctor drawn her into his macabre experiments? The police seize the few clues and Linda Merle is accused of murder. Bit by bit they build up the circumstantial evidence while the ingenious private detective Hermann Glide works in the background. By methods of intuition and a daring lack of scruple, Glide solves the mystery of the crime - a crime of passion and tragically warped mentality.