A year after the events of Lake Placid 2 at Black Lake, in Aroostook County, Maine, young couple April and Jason go skinny dipping and are attacked and eaten by a group of baby crocodiles. Meanwhile, at the house of the deceased Sadie Bickerman, her nephew Nathan, his wife Susan, and their son Connor, are cleaning out the house so they can sell it. However, Sheriff Tony Willinger soon arrives and convinces Nathan and Susan not to sell. Connor chases an escaped pet lizard down to the lake where he encounters the baby crocodiles, and begins to secretly feed them.