The Little Murders of Agatha Christie

Appointment with Death (Rendezvous With Death) (2x26)

:

When a young patient at Dr. Rodier’s psychiatric clinic is savagely murdered, Laurence investigates among the inmates. He is worried about his faithful secretary Marlène: she has stopped wearing makeup and styling her hair, and no longer seems to be enjoying life. Dr. Rodier’s diagnosis is formal: the woman is depressed. Laurence persuades her to check into the clinic. There, Marlène stumbles on the body of Clarisse, Dr. Rodier’s gorgeous wife, who has been strangled in the grounds.