Cassie and Sam look forward to Middleton's bicentennial Halloween Harvest Festival, a competition with the rival town of Blairsville. Grace and Nick also realize that this is their last Halloween in Middleton. Abigail, as new mayor, tries to outdo Martha, whom she replaced, and creates rivalries within the town.
When a 100-carat ruby, known as The Heart of Middleton, is stolen from the museum where the festival's gala is to be held, the town's Halloween romance suffers. Cassie suspects a Grey House guest is the culprit, but she believes it will all work out during the upcoming gala.
