After Amos decides to retire early, Cabot Cove gets flooded with dozens of poison pen letters, in an attempt to cover up the surprising murder of a young woman who owns the land that a historic lighthouse is located on. With the help of a visiting travel journalist, it's up to Jessica to aid the new sheriff, Harry Pierce, in figuring who the culprit is.

While visiting her nephew in New York, Jessica runs into a former student, Elizabeth Gordon, in town for a cosmetics convention. Visiting her apartment, Jessica finds Elizabeth murdered and her portrait defaced with lipstick.