Known as America's Agatha Christie, leading female crime novelist Mignon Eberhart co-wrote this faithful adaptation of her popular novel While the Patient Slept. It features a clever nurse (Aline MacMahon) summoned to a mansion when an elderly man (Walter Walker) has a stroke after reading a telegram from his disinherited son (Robert H. Barrat). The unexpected murder of his other son (also Robert H. Barrat) turns the nurse into an amateur sleuth as she joins forces with a handsome detective (Guy Kibbee) to uncover family secrets and find the killer.