The tragedy that happened at the March mansion, in the respectable quarter of Cardington Crescent, is almost incredible. After all, representatives of London's high society gathered here - the aristocratic hosts hosted Lord George Ashward and his wife Emily. There is no place for crime in such houses. And yet, one morning George was found dead - he had been poisoned. Without a doubt, the murderer is someone in the household. Suspicion immediately fell on Emily. After all, it’s no secret that George had an affair with the beautiful wife of William March in front of his own wife. And when Mrs. March herself soon dies, Emily's motive becomes obvious to everyone - jealousy. But she is determined to defend her good name. She calls her older sister Charlotte and her husband, police inspector Thomas Pitt, for help...