In the distant future of 10,001 B.C., a caveman desperately flees from a perilous predator across the plains. His journey takes an unexpected turn when he finds himself in a brawl with the wrestler Wolf. After triumphing over him, the caveman is confronted by a bizarre creature: a saber-toothed version of Amy Winehouse, who dramatically informs him that the world is set to end on August 29, 2008—the date of this movie’s release. She cryptically reveals that their destiny is tied to a mystical crystal skull.
The film then flashes forward to modern times, treating the initial scene as Will's dream. Will soon discovers that his girlfriend Amy is cheating on him with Flavor Flav, leading to a breakup fueled by his inability to express his genuine feelings. Later that day, despite being twenty-five, Will hosts a lavish "Super Duper Sweet Sixteen" party at his house, attended by a colorful guest list including Juney, Dr. Phil, Calvin, and Anton Chigurh. Chaos ensues when Seth and McLover make an attempt to swipe liquor from the festivities. Calvin’s girlfriend Lisa (portrayed by Kim Kardashian) pressures Calvin to eliminate the thieves, but amidst the confusion, he misfires and accidentally kills Dr. Phil, Chigurh, and the Beautiful Assassin, Carmen Electra.
As the evening progresses, a sudden tremor interrupts the celebration, plunging the room into darkness. A radio report warns guests of an impending meteor shower, marking the end of the world. This catastrophic event is vividly illustrated when Hannah Montana meets her demise by a falling meteor, bizarrely continuing her promotional pitch until her wig falls off, revealing her identity as Miley Cyrus in her final moments. Amidst this chaos, a child wakes up Hancock, who attempts to save the day but inadvertently knocks himself out instead.
The city begins to freeze, compelling the group to seek refuge in a garage, where they encounter the characters from Sex and the City, who express their intent to defend the place. A brawl erupts between Juney and Carrie Bradshaw, with Juney emerging victorious. During this struggle, she mentions global warming as a potential cause for their calamities, prompting Will to speculate whether his dream about Amy Winehouse is connected. As tensions rise, Calvin suggests the group remove their clothing to combat the cold, but only the girls comply, leaving the guys dumbfounded until Juney unexpectedly goes into labor.
In a series of surreal dreams, Will shares his true feelings with Amy but faces heartbreak when she evades him. After emerging from the garage, Will receives a call from Amy, expressing his love, only for the connection to sever before he can reach her. As the plot thickens, tragedy befalls the group when a meteor kills Lisa. The introduction of the Enchanted Princess shifts the dynamics, yet she is revealed to be a misled character rather than a royal, having survived through a chaotic life.
Once the whirlwind of events propels them towards the museum where Amy is trapped, they attempt to beat the ticking clock set by Batman, who insists they prioritize survival over rescue. Consequently, the gang hatches a plan to hijack Speed Racer's Mach 5, only to discover a surprise in the trunk—an amusing encounter with Michael Jackson and his familiar companions.
With newfound urgency, they navigate through the museum filled with awakened artifacts, encountering Kung Fu Panda along the way. A mix of humorous encounters leads to a climactic showdown with other characters, including an awkward meeting with Indiana Jones, who assumes a paternal role in Will's life. The narrative culminates with Will placing the crystal skull on the altar, averting disaster, and transitioning into a wedding ceremony between him and Amy, officiated by The Guru Shitka.
As the film draws to a close, the characters unite in a joyful rendition of the "Dating song", celebrating their bizarre, entwined relationships, while the antics of the Chipmunks cap off this uproarious journey.
