Major Palgrave, an unusual but charming mystery writer, revealed to Miss Marple that one of the guests at a luxurious Caribbean resort they were staying at was a Bluebeard-type wife murderer. Unfortunately, the Major succumbed to an apparent accidental overdose of alcohol and blood pressure medication before revealing the killer's identity. When it was discovered that the medicine belonged to another guest and the revealing photograph the Major was carrying was missing, Miss Marple realized that the serial killer had struck again and more murders would follow.