

The older son, Percival, admits that his father was senile and ruining the business. The younger Fortescue son, Lancelot, suddenly arrives from Kenya with his new wife. The other maid, Ellen, was bringing in the washing when she found Gladys' strangled with a stocking, and with a peg on her nose. She knew Gladys to be romantic and gullible. The next to be murdered is a maid named Gladys with whom Miss Marple was acquainted. Marple realizes the murders are arranged according to the pattern of a childhood nursery rhyme, Sing a Song of Sixpence. Going on the only clue, a pocket full of rye found on the victim, Miss Marple begins investigating. His wife was the main suspect in the murder, until she also was murdered, after drinking tea laced with cyanide.

The diagnosis is death by taxine - a poison found as a mixture of cardiotoxic diterpenes in the leaves, but not the berries (darils), of the European yew tree. When upper middle class businessman Rex Fortescue dies while having tea, the police are shocked.
