Early one morning, a young eccentric woman named Norma Restarik knocked on the house of the famous detective Hercule Poirot and asked to see him. She looked unwell—frightened, nervous, unstable. From her incoherent explanations, one thing could be understood: the girl doesn’t rule out that she has committed a murder. The trouble is, she can’t remember either the victim’s name, the circumstances of the killing, or the location of the crime. The murderer is there—but the murder itself has not been discovered. That’s what Hercule Poirot will have to deal with while searching for the crime.