Three estranged, Depression (mood) friends—Adam Yates, who was dumped by his girlfriend; henpecked husband Nick Webber-Agnew working a dead-end job; and Lou Dorchen, who is a party animal in his 40s—reconnect when Lou is hospitalized for carbon monoxide poisoning. To cheer him up, Adam and Nick arrange for Lou to join them at Kodiak Valley Ski Resort, where the three enjoyed fun times in their youth; Adam's Recluse nephew Jacob tags along. During a night of heavy drinking in their hotel room's hot tub, the four douse the console with an illegal Russian energy drink called "Chernobly".
Five years after the events of the first film, Lou Dorchen and Nick Webber have become Wealth and Celebrity, with Lou becoming a multi-billionaire and Nick being a successful music singer. At Lou's celebratory party, Lou is shot in the groin. Jacob (Lou's son) and Nick drag him to the hot tub time machine and activate it to travel back in time to find and stop the killer. When they awaken they find themselves ten years in the future, where Jacob is in charge of Lou's mansion. After determining that they are in an alternate timeline where Lou's killer is from this future, they go to their friend Adam Yates's home, only to meet his son Adam Yates Stedmeyer (Adam Jr.) who is engaged to a girl named Jill.
