In the summer of 2008, Sean Conklin and his classmates Tracy, Tyler, Bruce, and Ruthie decide to spent their last weekend together at a local lake after graduating from high school. Shortly after arriving, they head into the water, but Sean suddenly sees some tentacles splash out of the water, but no one else does and he dismisses it at first. Tyler finds a canoe and proposes that they go out to a floating platform in the lake to spend the rest of the day. Sean and Tracy discuss their future as they row out to the platform. Tyler attempts to scare them by pretending something has grabbed him and pulled him under, but they easily predict when he would resurface. As the day progresses, Ruthie is suddenly pulled underwater, and the group panics, but it turns out to be Tyler playing another trick. They scold him, and Tyler angrily leaves in the canoe, leaving no easy way for the others to return to shore. Sean tells them not to worry, as Tyler will probably return, but they suddenly hear a yell and see that Tyler is missing again, and the canoe has been capsized. They immediately assume that he is trying to play a prank on them again, but Bruce decides to see if he can find him. After swimming over to the canoe, he says that he cannot find Tyler, and suddenly starts yelling, claiming something is grabbing him from underwater, and disappears as well. Sean confides in the remaining two that he saw the tentacles from before, but they have no way of escaping from the creature (or possibly creatures) and resort to yelling for help as night falls. The raft is suddenly attacked, and Ruthie falls into the water. Sean and Tracy conclude that they have to try to swim to shore, or the creature will kill them anyway, but are attacked as they attempt to make the crossing. However, they were found on the shore, having survived drowning and were treated for exhaustion, shock, and unidentified blister-like wounds all over their bodies. The bodies of Tyler, Bruce, and Ruthie were never found.