A close-knit family, the Cassidys, had a daughter who was kidnapped by a cult of demon worshippers. They used her to summon a demon. The daughter escaped, and now the family huts the demon. The cult was connected with Lewis Vendredi, and used a secret cavern beneath Curious Goods for their rituals. The paths of the Cassidys and our intrepid trio cross when they track the demon to the store. The demon must be killed by midnight on a particular day, or it will remain on Earth forever. Ultimately, the demon is destroyed and the trio use the expanded space from the cavern to store more antiques, as the Vault was filling up.