Four friends head to Hawaii to investigate reports of a haunting at an abandoned resort in hopes of finding the infamous Half-Faced Girl. When they arrive, they soon learn you should be careful what you wish for.

When a meteor shower rains down outside Los Angeles, Jonas and Lars, two friends stuck in tired, boring lives, head out to find a meteor and strike it rich. After recovering one, they start being stalked by terrordactyls, ancient flying reptiles that launch a full-on assault on the city. Trying to survive, they go on the run...

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.