When a possessed pair of jeans begins to kill the staff of a trendy clothing store, it is up to Libby, an idealistic young salesclerk, to stop its bloody rampage.

To celebrate their graduation, the teenagers from Valley Hills High School have organized an ’80s-themed party in an old water park. Things grow gruesome when it turns out that a mysterious maniac has inserted giant razor blades into the water slides. The Wet Valley water park thus becomes the backdrop for a bloodbath (literally), and everyone is a suspect…