After a supper of canned lobster and a dessert of trifle, three people became ill. One of them, Mrs. Jones, died. A bout of botulism was suspected but could it have been more than that? Sir Henry Clithering, the former head of Scotland Yard, recounts this story of a recent case to the Tuesday Night Club assembled at Miss Marple's house in St. Mary Mead. The group are keen to delve deeper as he asks whether any of them can resolve it. In the corner sat Miss Marple, knitting and listening.