The Return of the Dead

Frank strikes the drum to impress new employee Freddy, trying to prove that the drum's seal is secure. This demonstration backfires catastrophically when the impact breaks the seal and releases the toxic Trioxin gas that had been stored in the warehouse basement for years after a delivery error.

The Trioxin gas seeps through the warehouse basement and causes a stored cadaver to melt, which then reanimates another corpse kept in a meat locker. The gas has the unique property of being able to reanimate dead tissue, even from fragmented bodies.

When Burt arranges for the zombie to be incinerated at the mortuary crematorium, the extreme heat releases the Trioxin toxin trapped in the corpse's body into the air. The gas then condenses and falls as contaminated rain, which has the ability to reanimate corpses in nearby cemeteries.

Trioxin reanimation creates zombies whose every body part remains independently alive and functional. When Frank, Burt, and Freddy attempt to kill the creature by puncturing its brain and dismembering its body, each piece continues moving and posing a threat, making conventional destruction impossible.

Exposure to Trioxin gas causes a unique paradox where the infected individuals appear clinically dead, showing no vital signs, yet remain conscious and aware. Paramedics confirm this horrifying state, describing them as dead but still present in their bodies as the reanimation process begins.

A restrained zombie explains that reanimated corpses can feel themselves decaying, which causes them constant agony. Feeding on the brains of the living temporarily relieves this pain, giving the undead a horrifying motivation for hunting humans beyond mere hunger.

As Frank feels himself becoming increasingly undead, he retains enough mental clarity to make a desperate choice. Knowing he will fully transform into a zombie and potentially harm others, he climbs into the cremator and commits suicide, ending his life before the reanimation process completes.

After contacting the number on the Trioxin drums, Burt reaches Colonel Glover, who explains that the zombie outbreak has become uncontrollable. The military deems the situation a threat to national security and orders a nuclear artillery strike on Louisville to destroy the outbreak at any cost.

The nuclear artillery destroys the immediate zombie threat to the survivors, but the intense fires from the blast release stored Trioxin into the atmosphere across a much wider area than before. The film ends with the toxic rain beginning again and zombies crying out from their graves, implying the contamination has spread far beyond Louisville.

As Freddy becomes increasingly infected with Trioxin and edges toward full zombification, he experiences the overwhelming hunger that affects all reanimated corpses. Driven by this desperate need and no longer fully in control of his actions, he attacks Tina despite their relationship.

When the zombie army led by Trash overwhelms the evacuation route, Burt is forced to make a desperate choice. He abandons Ernie and Tina in the attic to save his own life and Spider's, as the sheer number of pursuing undead makes carrying everyone impossible.

Spider gives the disfigured reanimated corpse in the warehouse basement the name Tarman, likely referencing its grotesque appearance and the toxic, tar-like substance that seems to ooze from its reanimated body as it moves through the basement.