It stars John Friedrich (Dennis Zorich), Rachel Ward (Margaret), Daryl Hannah (Windy Morgan), Adrian Zmed (Marco Cerone), Ernest Harden Jr. (Nathaniel Hines), Lewis Smith (Boone), Joe Pantoliano (Eggar), Akosua Busia (Vanessa), Mark Metcalf (Mike), Cindy Harrell (Melanie), Irene Sanders (Sammie), Richard Jacobs (Mr. Morgan), Donna Pinder (Mrs. Morgan), Jim Youngs (Jim), Lori Butler (Lori), and Tony Maccario (Eggar's Mother).
The boys search for him and the others search nearby the camp. Mike takes a swim and Melanie follows him. While having sex, Mike is stabbed by a strange creature, Melanie screams in terror while watching him die.
That night, while sleeping, Margaret is attacked by the strange creature. She confesses hysterically what she saw to the other campers. The campers hear a strange noise and pursue the source only to find Marco, who has returned to the camp. Vanessa gets angry at the guys for scaring the girls and walks off alone. She finds the old outhouse and enters, and Mike's severed head falls on her, causing her to panic and scream.
Burying Melanie near the river, The group continues onto the end of the river and find their empty, broken-down bus. They decide to spend the night there, but the creature attacks the bus. The creature gets inside but the group escape out the back door.
The group gathers supplies and camouflage themselves. Dennis climbs one of the highest trees, where he sees the long missing Marco, who was searching for Eggar. When Eggar appears, he begins to strangle Marco. The group attacks Eggar, suspecting he was the one who killed Mike and Melanie, but the real creature appears.
The creature rises up and screams, revealing to be Eggar's long lost mother. As she walks down to confront the group, she steps on one of the traps, killing her. Eggar appears to be devastated. Now, the survivors - Margaret, Windy, Vanessa, Nathaniel, Boone, and Marco watch in horror as Eggar's mother hangs dead in the trap.