When his family is murdered, a deaf-mute named Boy escapes to the jungle and is trained by a mysterious shaman to repress his childish imagination and become an instrument of death.

The story revolves around a Basque Roman Catholic priest dedicated to committing as many sins as possible, a death metal salesman from Carabanchel, and the Italian host of a TV show on the occult. These go on a literal "trip" through Christmas-time Madrid to hunt for and prevent the reincarnation of the Antichrist.

When his family is murdered, a deaf-mute named Boy escapes to the jungle and is trained by a mysterious shaman to repress his childish imagination and become an instrument of death.

After their first adventure with the "Hot Tub Time Machine," Lou and Nick are living very well off their ill-gotten gains, while Jacob still cannot rely on Lou to be a positive role model. When an unknown assailant breaks into Lou's mansion and shoots him, Nick and Jacob take him for another trip in the hot tub. They emerge in the year 2025, where they must figure out who shot Lou and prevent it from happening again.