Burt Wilson owned the dark Uneeda Medical Supply warehouse in an industrial park outside of Louisville, Kentucky. Just before closing time that Friday anticipating a big 4th of July weekend, Frank, the manager begins showing teenage Freddy the ropes of his new summer job-stock room clerk. Burt heads home after 5 P.M. in his convertible and Frank proceeds to show Freddy everything from skeletons to wheelchairs to veterinarian specimen dogs, and finally he opens the freezer locker where they store bald human cadavers in see-through bags... used for ballistic tests and medical school use.
Frank, seeing the obvious morbid interest Freddy displayed at the cadavers, decides to reveal another dark little secret about the company. He tells of a chemical accident at Pittsburgh's VA Hospital in 1969 in which Darrow Chemical Company was developing a defoliant from the chemical 2,4,5 Trioxin, which instead leaked into the morgue, animating some of the bodies. The Army Corps of Engineers contained the bodies and dirt and began shipping them out, and some accidentally arrived at the warehouse in metal canisters.
Under Burt's orders, they've been in the basement all these years rather than being sent back and associated with contaminated corpses. In fact the very incident had inspired Night of the Living Dead a few years later, though its content was exaggerated. When Freddy shows distrust of the often-kidding Frank, he is shown the canisters first hand when something happens. Frank slaps the side of the aging tank and they are both sprayed in the face by a greenish vapor, leaking full force from the once-welded areas. The fumes fill the air vents of the building and the men are unconscious for an hour.
Meanwhile Freddy's girlfriend Tina is hanging out with punkers Chuck, Casey, Trash, Scuz and Spider. Deciding how to spend their Friday night, Tina mentions Freddy's new job. Knowing Fred is quite the partyer, they plan to go pick up calling on the driving talents of Suicide, a particularly adventurous punker who "lives" up to his name, almost driving into an oncoming train. Later, the teenagers wait around in the nearby Resurrection Cemetery, dancing and loitering throughout the cluttered tombstones standing in this unkept and defaced mess of a resting place, Frank and Freddy regain consciousness.
Noticing the body in the tank
must have melted they go back upstairs when they discover the place is rank with
the stench of the Trioxin gas. Then they hear a sound...barking...from the stock
aisles. There on the floor they are horrified to see one of the specimen dogs animated...lying
helplessly. Not only that but the specimen butterflies are moving around around
too! The men are immediately distracted by the agonizing cries of a man nearby
banging on a door...and it is coming from the freezer locker.
The men are at their wit's end. Frank warns Freddy about calling both the police and the number on the side of the tank (the military), explaining that that would jeopardize the business of Uneeda, whose reputation is among the best. He phones the boss to get to the warehouse, calmly telling Burt, "We have a little problem." Burt arrives and though quite angry at Frank's actions, he decides that they will have to get rid of the evidence to preserve the business’s reputation. The cadaver and the split dogs will have to be destroyed. But how? Burt recalls vaguely the corpses in the movie Night of the Living Dead were killed by a bullet to the brain. Burt immediately grabs a pick axe and the men unlock the freezer releasing the cadaver who runs out and attacks Burt. The creature is pulled off of him by Frank and Freddy and held down so that Burt can put the naked, moaning corpse out of its misery. With one swing, the ax cracks right through its bloodless skull...
But the yellow cadaver is not dead. Pinned to the ground, the cadaver kicking and screaming even more, the men realize "the movie lied!" They can't be stopped this easily. Burt takes the next step and severs its head with the bone saw. At which point the body gets up and runs through the aisles like a headless chicken. The men finally tackle the body and tie it up. What to do now? Frank suggests dissolving the body with acid but the task would be too long; it may not even eliminate it all. Then Burt remembers his friend Ernie Kaltenbrunner, the embalmer across the street at Resurrection Funeral Home. The body needs to be cremated with his help.
Burt enters the funeral home and gets a quick lesson in rigor mortis with the body his embalmer friend is working on. Burt at first tells Ernie that inside the bags his men has brought in are rabid weasels that have accidentally been shipped to the warehouse. Ernie refuses to burn them alive in the crematory and Burt reveals one of the dismembered arms of the cadaver which immediately attacks Ernie’s leg. The chemical is still inhabiting the bodies and even transcends the cremation process and reappears again out of the smoke stacks, rising into the atmosphere and causing a thunderstorm of acid rain, which falls below to the cemetery nearby. Tina had already taken a walk to Uneeda to find Freddy; the teenagers run for refuge in Suicide's convertible.
Ernie begins removing the
cremains, Burt suggests cleaning up Uneeda and heading for home when Frank and
Freddy reveal just how violently ill they have become. Hit in the face with this
strange chemical, they were now looking pasty and experiencing pains not unlike
those of severe botulism. The paramedics are called in immediately. Meanwhile,
the teens start to hear strange noises coming from the graveyard, though hard to
decipher over the rain. Suicide's car roof begins to leak, they take off to
Uneeda hoping to find Freddy. There they hear the cries of Tina screaming from
down in the basement. It is here where the gang encounters one of the nastiest
sights they will ever see....
The mummy from inside the tank had escaped after the meltdown. It was standing right there in front of them, black tar running all over, bones protruding, walking as if it was going to fall into a pile of bones any minute. But it was hungry for brains and Suicide was the nearest one in sight. After seeing their ride attacked and twitching on the ground before them, they get the next shock when the Tar Man realizes that they're in the room, calling out gleefully in a vomit-like voice, "more brains!" Running back to the cemetery the gang hears a gargling sound coming from one of the tombs.
The rotten remains of the deceased were breathing their first gasps of life again between intervals of lightning. From nearly every tomb, hands, heads, and bodies crawled out, letting out shrieks of pain and agony...and pleas for BRAINS! Soon the entire cemetery had corpses of all kinds reaching for the teens, now running for their lives in every direction. Two went straight back to Uneeda, being chased by a horde of the living dead...also running.
At the funeral home, the paramedics are doing vital signs on Frank and Freddy when they realize that either their equipment is bad, or these men are truly dead. "No blood pressure, no pulse." Their nervous system just seemed to have been shut down. Just as they hear banging on the front door of the mortuary, the medics go back to the ambulance parked out back to get some stretchers.
Ernie goes to the front door armed with his Walther pistol. He opens the door and three teens, Scuz, Spider and Tina are standing there. Spider tells him that he needs to lock all the windows and doors, and that there's dead people screaming and they're after them. Ernie realizes the zombie problem has just begun. They return to the embalming room where Tina is joyed to find Freddy although she is unaware of his condition. Ernie goes outside to check on the medics. Sensing something wrong again in the dead silence...he shuts the open ambulance door and is immediately horrified at the sight before him. A medic's brain falling out of the mouth of a decayed man screaming right back at him. Firing his gun, he realizes the body cannot die. It's following him up to the back door of the mortuary. And it is hobbling on stumps of were once legs!
The veteran mortician is shaken and horrified and attempts to call police. But the phone lines are dead and then the windows crash through...
The group almost instinctively board shut the windows in the mortuary and the stained glass ones in the chapel as if subconsciously recalling the actions taken in Night of the Living Dead. A corpse, supplied with fresh brain food outside, overhears the ambulance radio, and calmly and wisely tells the dispatcher to "Send more paramedics".
There seems no way of stopping the army of corpses which surround the mortuary, killing off the next group of paramedics and the police officers that follow them ("send more cops"). When Frank and Freddy are diagnosed with rigor mortis by the resident mortician, they are locked up in the chapel. Tina is locked up too with her boyfriend. A few minutes later , they capture a lady corpse which gets chopped in half at the waist while fatally attacking Scuz through a window in the casket storage room.
The now naked half lady, with flowing blond hair still intact and bright blue eyes, is tied to the embalming table and Ernie's chilling interrogation starts: "Why do you eat people?" …"Not people... brains... it makes the pain... go away.. Ernie: "It hurts to be dead?" "…I can feel myself rot." (Author’s note: There you have it, straight from the corpse’s mouth).
Outside, the rain keeps creating
pools full of the chemical, reviving the now ghost- white body of Trash. In the
chapel, Freddy realizes the only way to relieve the suffering he is
experiencing: he attacks Tina. When the men come to her aid, Ernie throws
sulfuric acid on Fred's face and locks him up in the chapel not realizing Frank
has escaped during the struggle.
Fred, blinded and scarred by the acid breaks out of the chapel as Ernie and Tina lock themselves up in the funeral home attic. Frank has hid himself in the crematorium and proceeds to commit suicide. Breaking out of the mortuary in the patrol car out back, Spider and Burt break for Uneeda and there they meet up Casey and Chuck. The police blockade had just started in the industrial park, with helicopters and a Tac Squad wait for the attackers to appear. Burt becomes the Louisville Slugger literally lopping off the head of the Tar Man in the basement. Now by a phone in the basement, they call the police in the blockade but after a moment they hear the screams. First the ranting dead's, then the police officers.
As a last resort, Burt calls the stenciled number on the tank. He is connected with Sgt. Turner and then Colonel Glover, who we saw earlier in a scene inside his mansion in San Diego. Glover was part of the operation that contain the VA Hospital accident in the sixties. That group is still searching for the lost consignment of "Easter Eggs". A telecommunications system is set up in his estate in case, after all these years, someone actually calls that now nearly 20-year old number. After briefly describing the situation to the Colonel, finally confessing all the information he's bottled up so long, Burt is transferred again and put on hold.
The damage is assessed and the military decides the world is not prepared for hatched Easter Eggs. Approximately twelve hours after Frank and Freddy first reached the tank, there was no more Uneeda. No more Resurrection Funeral Home or Cemetery. No more Louisville. No more Jefferson County.
A low-yield missile was ordered into the area. A petrochemical explosion is reported to have caused this disaster...and the military affirmed the rain will wash everything away...but what kind of rain? Could a cremation of this magnitude start it all over?