A wealthy Greek businessman is found dead in his London home. The Leonides were a large, happy family living in a sprawling, dilapidated mansion. This changed when the head of the household, Aristide, was murdered by a lethal barbiturate injection. Naturally, suspicion falls on the young widow of the old man, who is fifty years his junior. However, the murderer did not anticipate the tenacity of Charles Hayward, the fiancé of the deceased millionaire's granddaughter.