At Chicago's North Avenue Beach, the lifeguards are the law. These ragtags will do everything in their power to make sure you don't go out past your waist. Best friends Hughie (the hopeless romantic) and Otis (the ladykiller) get caught in one love triangle after another as young vixen Maggie and tomboy May make it hard for them to keep their eyes on the water at all times. As the summer sun heats up, so does tension among the crew, and their despotic superiors make sure that's it's never just another day at the beach.

Two sisters and their boyfriends drive to a small cabin to spend the weekend with the girls parents. However, when they arrive, they find them missing and the cabin in disarray. Things worsen as they become stranded at the remote lake, cars not starting, cell phones useless. As the autumn sun fades away something creeps from its lake dwelling in search of blood... human blood. And while the mystery of what happened to the parents unravels so too does the bond of friendship as pasts crash in on the present. Not everyone will survive the night, but those that do will be dead in the water.