ZOMBI 3

In a covert biological weapons laboratory in the Philippines, scientists work on a serum called Death One, which reanimates the dead. When Dr. Alan Holder and his assistant Norma experiment on a deceased human test subject, the corpse reanimates and reacts violently, prompting Dr. Holder to resign from the project. As he prepares to surrender the serum to the military, a group of rival gunmen ambushes the facility, with the lone surviving criminal absconding with Death One.

During the ensuing chase, gunfire breaches the container with the serum. Dr. Holder initially shows no concern about the virus escaping in this manner, given its inability to survive more than 30 seconds in the presence of oxygen, until he learns that the criminal accidentally touched the serum and became infected. General Morton and his soldiers arrive at the Sweet River Resort, where the criminal had fled, to find that the criminal had infected a bellhop, killed a maid, and cut off his own hand in a failed attempt to stop the infection's spread before finally succumbing to the infection. Morton orders the patrons and staff to be killed and buried in a mass grave, and the criminal's remains are transported to the facility's incinerator. As Dr. Holder and Norma fear, the ashes disperse into the air, infecting an entire flock of nearby birds.

Meanwhile, a trio of G.I.s on vacation are looking for girls and encounter a nearby bus, whose passengers include Joe, Nancy, Carol, Lia, Suzanna, Jane, Jane's boyfriend Tom, and bus driver David. Nearby, a tourist named Patricia and her boyfriend, Glenn, discover the dead birds, which reanimate and attack them. The birds assault the bus while the G.I.s attempt to evacuate it, and Lia is bitten. Patricia and Glenn stop at a nearby garage but flee when a machete-wielding zombie attacks Patricia, and the garage explodes after she sets the zombie afire. The G.I.s and the bus party stop at the now deserted Sweet River Resort. The men find a crate of guns left behind by the soldiers and begin fortifying the resort while Carol and one of the G.I.s, Bo, drive off to seek help.

When their car breaks down, Carol goes looking for water but is mauled by zombies and becomes zombified after her legs are torn off. Bo flees as more zombies emerge, eventually joining Patricia and Glenn. Glenn dies and reanimates as a zombie on the way to the hospital, killing Bo while Patricia escapes.

Back at the lab, Dr. Holder and his team start work on an antidote to Death One. Meanwhile, Morton's men initiate an operation to eradicate the zombies, now identified by the codename "locusts", referencing the zombies' behavior pattern of swarming from town to town.

Jane and Tom are ambushed and killed by a zombie's head in the kitchen freezer at the hotel. Lia reanimates, kills, and devours Susanna and almost kills Nancy before being thrown off the balcony and killed. Kenny and Roger encounter Patricia as she arrives to break the news about Bo's demise, but zombies swarm the hotel. Before fleeing, Kenny, Roger, Patricia, Nancy, and David kill many zombies by using their newly acquired weapons.

The next morning, the survivors encounter some of Morton's soldiers, who kill David as he playfully chases a chicken. The other four escape as the final stage of Morton's zombie eradication begins, and Dr. Holder fears the atmospheric infection may not be confined to the island. Arriving at the nearby hospital, the four encounter a pregnant woman in labor. As Nancy helps deliver the newborn, Patricia battles zombie Glenn and beheads him, while Kenny and Roger battle Morton's cleanup crew. Nancy is mauled from behind by a zombie that sneaks behind her and is subsequently killed by the zombified newborn when it escapes the mother's womb. Meanwhile, Kenny, Roger, and Patricia escape to find more zombies. They make it to a helicopter, but only Kenny and Patricia escape, as Roger is attacked by the zombies while trying to join them and is killed by the cleanup crew, even after he begs the latter to spare his life.

Blue Heart, the DJ who provided commentary for much of the film, dedicates his next record to "all the undead around the world", having been infected himself. Upon hearing the broadcast, Kenny decides to return to the island, assuring Patricia that he intends to save what's left of humanity.