CBS Films has purchased William Penick and Chris Sey's script HELLFEST, reports ComingSoon.net. The story takes place at an amusement park, which is all decked out for Halloween, including roaming monsters to scare patrons. But when a real killer starts slashing visitors, the guests don't know what is real and what is not.

Penick and Sey wrote the screenplay based on an idea from Valhalla Ent.'s Ben Roberts. Valhalla's Gale Anne Hurd will produce. Mark Ross and Alex Ginno are shepherding for CBS Films.