Young Carl Fredricksen is a huge Charles Muntz fanboy.
Muntz, we learn through newsreel footage, is a famous explorer who recently returned from South America, where he discovered a rare, magnificent bird. There’s just one catch: Nobody believes him. So Muntz heads back to South America, vowing not to return until he’s caught that mind-blowing bird. Carl’s stoked.
On his way home from the movie theater, Carl meets Ellie; a plucky young girl that’s equally jazzed about Muntz and all things adventuresome. They strike up a fast friendship, and Ellie makes Carl promise that one day he’ll take her to South America—specifically Paradise Falls—in a blimp. She pins a grape soda bottle cap on him to solidify their friendship. It’s like a blood oath, but with soda.
So yeah, it's nothing like a blood oath.
Carl and Ellie grow up and get married, and through montage, we watch their life story: fixing up their house, picnicking on a hill, trying—and failing—to have a baby. They start saving their loose change in a jug marked Paradise Falls, but life keeps getting in the way. Car problems, broken bones, and home repairs force them to continually dip into their savings.
Old and gray, Ellie dies, and Carl’s left all by his lonesome.
[This is where everyone over the age of 16 breaks down sobbing, while all the kids in the audience look around wondering why the adults are such a bunch of softies. Just FYI.]
After the moving marriage montage, which packs a whole lot of living into its compact, heartwarming, and heartbreaking four-minute run-time, we fast-forward to the present, and Carl 2.0.
In his solitude, he’s turned into a first-rate grump.
Carl’s house sits in the middle of a noisy construction zone, but he refuses to sell the ol’ homestead. A wilderness scout named Russell shows up, offering to help Carl so he can earn his Assisting the Elderly badge. Carl refuses that, too.
After Carl smacks a construction worker with his cane, he’s sentenced to live out his golden years at the Shady Oaks retirement home. But wait—Carl’s got a plan. He attaches thousands of helium balloons to his house, and when the Shady Oaks folks arrive to whisk him away to a future full of cafeteria food and Bingo cards, Carl and his house take to the sky. His destination? Paradise Falls.
But there’s a catch: Russell has accidentally stowed away on Carl’s floating abode. They pilot through a nasty thunderstorm and land on a cliff opposite Paradise Falls. As they drag the house toward the falls, they add two more to their motley crew: Kevin, a huge exotic bird, and Dug, a talking dog. It turns out Dug is part of a pack of dogs that are hunting Kevin.
Eventually, the dog pack finds Carl and his crew and takes them back to their master. Surprise—their master is Muntz, and that creature he’s been chasing all these years is none other than Kevin. Muntz captures Kevin, and Carl and Russell run for it. They make it to Paradise Falls, but Russell is supremely bummed that Carl let Muntz nab Kevin. He decides to go back and save his birdie buddy.
After finding Ellie’s childhood Adventure Book, and a note scrawled inside encouraging Carl to have a new adventure now that she’s gone, Carl zooms after Russell in his house. Muntz captures Russell, making the score Muntz: 2, Carl: 0. With his house tethered nearby, Carl and Muntz duke it out on Muntz’s airship, and Carl rescues Russell, Kevin, and Dug. Carl’s house is cut loose in the struggle and drifts away. Muntz plummets to his death.
Carl and Russell fly back to the States, and Carl stands in for Russell’s deadbeat dad at Russell’s Wilderness Explorer ceremony. Instead of pinning Russell with his Assisting the Elderly badge, Carl bestows upon him the highest honor that he can: The Ellie Badge (aka the grape soda bottle cap that Ellie had given him decades before). Then they hit Fentons for ice cream. The final shot shows that Carl’s house made it to Paradise Falls after all, just like Ellie wanted.
The [sobbing like mad] end.