When James whisks Agatha away on a seaside trip to work on his new book, the last thing she expects is to end up in a town called Snoth-on-Sea. The getaway goes from bad to worse when they're greeted by protesters at the hotel, and then an obnoxious fellow guest is murdered-and the local police consider Agatha the prime suspect.

Agatha, Roy, and Sarah attend the Fruit Preserve Festival, where Charles and James are two of the judges for the jam competition, and DCI Wilkes is one of the competitors. After a few rounds of tastings, however, the judges start to act out, hallucinating-and Dr. Stevens, believing she can fly, jumps from the roof. DCI Wilkes employs Agatha to find the killer, as he's currently in the frame.