Quick recap
Elspeth McGillicuddy, a friend of Miss Marple's, looks out her train window and sees a man strangle a woman on a train running alongside. No body is found. Marple works out that it was thrown off near Rutherford Hall, the Crackenthorpe estate, and sends the capable Lucy Eyelesbarrow there as housekeeper. Lucy finds the body in a sarcophagus in the barn. The family, full of heirs waiting for their miserly father to die, becomes a target: two brothers are poisoned. Marple proves the killer is Dr. Quimper, the family doctor. The dead woman was his wife, who wouldn't divorce him, and he meant to marry Emma Crackenthorpe.
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