After an apocalypse nearly destroys the planet; the dead are resurrected as a result of lasting radioactivity. Without an effective means of destroying all zombies, an organization simply known as Undead Manor presents a solution. The mastermind of the facility offers families with a means of containing their undead loved ones by housing them in memorial cells. However, a group of guests invited to tour the facility, soon discovers that this service comes at a high price. One by one the undead begin to escape their cells, and the guests must ban together in order to survive the Attack of the Radioactive Zombies.