At a charity show, private eye Harry Bittercress flaps his arms and crows like a rooster while a stage hypnotist has him under. The audience roars. Cardamine, his wife, laughs until her sides ache. But then something devious occurs: a post‑hypnotic suggestion is planted in his mind — one that, when triggered, will compel him to assassinate a city official. Will Cardamine realize what’s happened in time to stop Harry?