Little boy Carl was mad about adventure from childhood, hoping to be a great adventurer.
One day, he encountered tomboy Ellie with enthusiasm for adventure. Ellie shared her dream place with him, "Paradise Falls, a land lost in time" . "That's it! You can take us there in a blimp! Swear you'll take us! Cross your heart!" Ellie said with great excitement. Carl nodded obediently. That promise bound them together ever since.
Gradually, they fell in love with each other. The same hobby eventually made Carl and Ellie a lifelong couple. They transformed the shabby cottage where love and dreams sprouted into a warm home. They spent years adding furniture to the flying house, leading an ordinary and happy life, from newlyweds to preparing to give birth to new life to the gradual aging of the two people.
Carl and Ellie shared a common desire to explore the "Paradise Falls" in South America. However, that dream never came true when Ellie was alive.
After Ellie passed away, the government planned to rebuild the place where Carl lived. But Carl was unwilling to leave the house which beared the memories of Ellie. "Tell your boss he can have our house, when I'm dead!" Carl said angrily. A few days later, Carl was forced to go to a nursing home after accidentally injuring someone. Before leaving, "I wanna say one last goodbye to the old place," Carl said to the worker of the nursing home and closed the door. A few minutes later, a shocking picture emerged—Carl lifted his house into the sky with colorful balloons, resolving to realize their unfulfilled dream.
While he was enjoying this great journey alone, suddenly there was a knock at the door. Carl opened the door and looked around. Suddenly, he found a boy clinging to the window as he was about to be blown down. It was Russell, an overly optimistic 8-year-old boy, who called himself the "Wilderness Explorer". Carl had seen him just a few days ago. And he still remembered that when he first saw Russell, he seemed to see the shadow of himself in Russell's body. They all shared a great passion for adventure. "Please let me in." Russell said tremblingly. For the sake of mercy, Carl had to take Russell with him on this thrilling adventure.
While walking through a forest, they encountered Kevin, a giant flightless snipe, who was extremely fond of chocolate. And Dug, a talking dog, who was commanded to catch snipes. They added pleasure to the journey.
However, what was behind this was Charles Muntz's malicious scheme, who was the idol of Carl in the past. They found that Muntz was a bad man who would do anything to get what he wanted. Knowing they had seen Kevin, a beautiful bird he wanted to catch to prove himself, "These people who pass through here, they all tell pretty good stories. A surveyor making a map. A botanist cataloging plants. An old man taking his house to Paradise Falls. "Muntz said threateningly to Carl, throwing a helmet at Carl's side,"I mean, that's the best one yet. I can't wait to hear how it ends." Soon after, Carl, Russell, Kevin, Dug and the flyhouse began their escape journey.
Thanks to Kevin and Dug, they were out of danger temporarily. At that time, Cral was just one step away from his dream place.
Carl read through Ellie's adventure diary and saw a message she had left for him,"Thanks for the adventure, now go have a new one!" Shocked and relieved, he made up his mind to leave the past behind and move on toward the future.
Eventually, in order to save Russell and Kevin, Carl gave up his flyhouse, gave up his dream, and even gave up the memories with Ellie. Seeing his flyhouse falling down slowly, Carl said calmly, "It's just a house", as if he had let go of the past. He moved on from the past and started a new journey.