Little Murders by Agatha Christie: Ding Dingue Dong

SINOSSI

A patient is brutally murdered in Dr. Rodier's psychiatric clinic. As Marlène is suffering from depression, Swan Laurence persuades his faithful secretary to become a patient at the establishment. Shortly afterwards, Rodier's wife is murdered. Laurence, who was her lover, is immediately the prime suspect; adapted from "Evil Under the Sun."