When foreman Frank shows new employee Freddy a secret military experiment in a supply warehouse in Louisville, Kentucky, the two klutzes accidentally release a gas that reanimates corpses into flesh-eating zombies. As the epidemic spreads throughout the town, and the creatures satisfy their hunger in gory and outlandish ways, Frank and Freddy fight to survive with the help of their boss and a mysterious mortician. When two bumbling employees at a medical supply warehouse accidentally release a deadly gas into the air, the vapors cause the dead to rise again as zombies.