Mr. Fortescue died during his morning tea in his office and the diagnosis was that a poison, taxine - a poison found as a mixture of cardiotoxic diterpenes in the leaves, but not the berries (arils), of the European yew tree - had killed him. His wife was the main suspect in the murder, until she also was murdered, after she drank tea laced with cyanide. Her lover, Vivian Dubois, was the suspect next, as well as just about everyone that knew the family. Going on the only clue, a pocket full of rye found on the victim, Miss Marple begins investigating. Marple realizes the murders are arranged according to the pattern of a childhood nursery rhyme, Sing a Song of Sixpence.