Zed and Addison are in their final year of high school at Seabrook High, a town that has become a safe haven for monsters and humans alike. Zed is looking forward to receiving an athletic scholarship that will allow him to become the first Zombie to attend college, while Addison is preparing for Seabrook's first international cheer-off competition. Then, all of a sudden, extraterrestrial beings appear in the vicinity of Seabrook, causing something other than friendly competition.