Sofia buys a skeleton key from spooky store Frightville that promises to open any lock. There's a mystery trunk in the attic of the big, old house her dad is turning into a bed-and-breakfast. Sofia is dying to see what's inside. To her delight, the key works on the trunk! But her joy quickly turns to terror when it seems like something may have been released from the trunk. She hears odd noises in the middle of the night and sees strange things around the house. Is it her imagination? Or could it be a ghost?