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.

A group of kids discover one of the drums containing a rotting corpse and release the 2-4-5 Trioxin gas into the air, causing the dead to once again rise from the grave and seek out brains.

Having recently witnessed the horrific results of a top secret project to bring the dead back to life, a distraught teenager performs the operation on his girlfriend after she's killed in a motorcycle accident.

In an attempt to rescue their friend from an evil corporation, a group of teenagers end up releasing a horde of bloodthirsty zombies.

A student creates and sells a drug called 'Z' which has the unexpected side effect of resurrecting the dead as flesh-eating zombies, who proceed to wreak havoc at a Halloween rave.