A group of high school students, led by prankster Steve and his friends Kevin and Katie, stumble upon a government experiment gone wrong when they inadvertently revive a decomposed, cannibalistic humanoid underground dweller, referred to as Bud the Chud. The students find Bud's body in a military lab and decide to take it for a joyride, thinking it was just a prop. Unbeknownst to them, Bud is part of a secret government initiative to create super-soldiers out of the dead, making him not just undead but more resistant and stronger than any ordinary zombie.

As Bud regains consciousness, he embarks on a spree of mayhem and human consumption, transforming those he attacks into fellow Chuds. Steve, Kevin, and Katie realize the gravity of their mistake as the contaminated population grows rapidly. With townsfolk turning into Chuds at an alarming rate, the students must team up with the local authorities to contain the outbreak and prevent Bud from leading his new army to conquer the town. Desperation mounts as they search for a way to stop the spread of the Chud virus before it obliterates their community entirely.