Zed and Addison are in their final year at Seabrook High, a town that has become a safe haven for monsters and humans alike. Zed is hoping for an athletic scholarship that will allow him to be 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 around Seabrook, causing something other than friendly competition.