When a mysterious thunderstorm unleashes an ancient alien virus that has previously wiped out entire civilizations, the world is plunged into chaos as bats grow into terrifying giant carnivore monster bats. As humanity teeters on the brink of extinction, a small group of survivors must band together to fight for their lives against these monstrous creatures born from radioactive radiation and atomic mutation. With the fate of human history hanging in the balance, the battle between humans and gargantuan bats becomes a desperate struggle for survival.