One of the "Tonight at 8:30" series produced in London and New York. In psychiatrist Christian Faber's drawing room sits his weeping wife and his sad assistants, waiting for the siren Leonora. In four flashbacks the story emerges: Leonora, a girlhood chum, visited Christian's wife and was introduced to him. She set out to capture her friend's husband but was captured herself. She threw him over because of his jealousy. He jumped out of the window. Leonora has come because Christian calls for her on his death bed. She returns slowly from his room to announce he has died and that his last words were tender ones to his wife, for whom he mistook Leonora.
The Astonished Heart was first produced as one of a series of nine one-act plays under the title Tonight At 8:30 at the Phoenix Theatre in January 1936 under the direction of Noel Coward.