Cassie receives an unexpected visit from her college roommate Autumn Delaney (Lolita Davidovich), who harbors resentment toward Cassie over a past event. Martha plans a bonfire to honor the season and tries to ignore her husband's failure to recognize the anniversary of their engagement on Halloween night. Bad luck seems to thwart Sam's attempts to plan a romantic Halloween for Cassie, their first as a married couple, despite the arrival of a mysterious good luck charm.
Donovan makes a wager with Abigail over the Halloween-themed triathlon he is racing against Sam, with the winner earning the rights to decide the couple's Halloween plans. Stephanie and Adam rally the town to break the pumpkin carving record held by Blairsville. Meanwhile, George and Nick search for Middleton's mythical sea monster. As the bonfire nears, Cassie helps Autumn overcome the past and take control of her future.