A detestable businessman is murdered while at work, and a handful of rye is found in his pockets. Soon after, members of his household fall victim to a killer intent on recreating scenes from a popular nursery rhyme.
A village is plagued by a spate of seemingly accidental deaths, but Miss Marple is convinced a more sinister hand is involved when a villager on her way to Scotland Yard is conveniently dispatched.
A reformatory for delinquent boys run by Miss Marple's philanthropic friend becomes the scene of arson and poisoning, and ultimately murder.
The cryptic final words of a dying man lead Miss Marple and two young adventurers to a dysfunctional family harboring dark secrets.