When their scientist father moves them to a new home next to a swamp, Kelli and Shawn hear stories about a terrifying, ancient beast that inhabits the muck and the pair try to convince their father to move them out before it strikes.

"What do Zoey and Billy Traister do when they find an abandoned ventriloquist dummy in an empty lot? They take him home, of course! As the pair tries to figure out why someone would throw out a perfectly good dummy, they accidentally bring Slappy to life. A night of horror ensues until the siblings put Slappy back into his case. But when they find Slappy's diary and clues that could lead to gold, they'll have to find Slappy's second diary while evading...