Kelly and Jack share a moment of awkward intimacy as Kelly dresses Jack's cut. Suddenly a giant crocodile leaps out of the water and drags the bear back into the lake. Jack pulls Kelly out of the way, but the bear looms over them. During the brawl, Hank chases Hector to the lakeside and as the others follow, a grizzly bear appears.
Hector's attempts to console him backfire and anger him, and they get into another fight. Hank mourns the deputy and blames himself for his death. Jack and Hector come back up separately and while removing the speaker, Burke is attacked by the creature and his head is bitten off. Kelly falls overboard, but is saved just in time as the croc was preparing to attack. It pulls the boat anchor, but Hank orders his deputy Burke to cut the anchor cable and the boat escapes. The creature is shown sneaking up on them. After the two enter the water, a speaker producing the sound of baby crocs in distress is placed in the water. The next day Jack and Hector go diving in the lake to find the creature. After the two are broken up, Kelly tells Jack and Hank that Hector believes crocodiles are godly creatures (since he's never been bitten by one).
That night, due to his antagonistic nature and free spirit, Hector angers Hank and the two get into an argument. Hector's radar begins to pulsate as Kelly and Hank are thrown off their canoe and into the water. While the four are out exploring the lake, the creature is shown settling under Kelly and Hank's canoe. Later that afternoon, a helicopter arrives at the camp where we are introduced to Hector Cyr ( Oliver Platt), an eccentric mythology professor, flamboyant multi-millionaire and crocodile enthusiast who believes, despite Hank's intense skepticism, that the creature doing the attacks is indeed a crocodile. They also meet Delores Bickerman ( Betty White), one of few people living on the lake, who claims to have killed her husband. Upon arriving in Maine, Kelly informs Fish and Game officer Jack Wells ( Bill Pullman) and Sheriff Hank Keough ( Brendan Gleeson), who himself witnessed the fatal attack, that the tooth appears to be reptilian in nature, and is not a fossil, but something much more recent. Paleontologist Kelly Scott ( Bridget Fonda) gets the job, mainly because her boss, with whom she has had an office affair, wants her out of his way so that he can pursue another relationship with one of Kelly's co-workers. A tooth is found in the diver's remains and, as it appears to be a prehistoric fossil, a request is made for assistance to the Natural History Museum in New York City. An officer of Maine Fish and Game researching American beaver populations is scuba diving in Black Lake, Aroostook County, Maine, when he is savagely attacked and bitten in half by something unseen in the water.