It's the week of Halloween and the 10 year anniversary for the graduates of Purity County High School. Stacy and her friends gather for a celebratory toga party to reconnect. But when her ex-boyfriend, Nathan shows up with his buddy, AJ things take a turn for the worse. After Nathan has an altercation with the socially awkward Dereak and his childhood best friend Eric, Dereak storms out, and a masked killer shows back up to crash the party. Now Stacy and her friends find themselves in a fight for their lives.