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."

On Christmas eve, strangers find themselves trapped in a holiday-themed museum where they discover that the animatronics have a will of their own.