Quick recap
Wealthy Rex Fortescue dies at his office after his morning tea, poisoned with taxine, the poison in yew. His pocket is full of rye grain. Soon his young wife, Adele, dies with cyanide in her tea, and the maid, Gladys, is found strangled with a clothespin on her nose. Miss Marple, who once trained Gladys as a maid, comes to the Fortescue house and shows Inspector Neele that the murders follow the nursery rhyme "Sing a Song of Sixpence." The killer is Lance, the younger son, who used Gladys, in love with him, to poison his father. At the end, a letter from Gladys arrives with a photo of her boyfriend: it's Lance.
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