Pixar movies are not safe from a variety of theories, most of them making their stories sadder, as is the case of Up, which made way for a theory that makes its already sad story even more tragic. Pixar has become a powerhouse in the world of animation, and each of its movies features relatable characters with stories that always offer a heartfelt message. In 2009, Pixar brought one of its most heartbreaking movies with Up, directed by Pete Docter, and which like most Pixar movies, was a big critical and commercial success.

Up introduced viewers to Carl Fredricksen, a 10-year-old boy who idolizes explorer Charles Muntz. One day, he meets Ellie, a fellow Muntz fan to whom he grows closer and closer, and they eventually marry. Carl and Ellie shared a dream of traveling to Paradise Falls, so they started saving to make it happen, but as years passed, they came across various obstacles and situations that forced them to spend that money. Many years later, a now-retired Carl is about to be sent to an assisted living facility, so he decides to turn his house into a makeshift airship with the help of hundreds of helium balloons and flies away, hoping to make it to Paradise Falls. However, Carl ends up being accompanied by an unexpected visitor: Russell, an eight-year-old “Wilderness Explorer”.

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Up was a success with critics and viewers, who praised it for its story, animation, characters, themes, and Michael Giacchino’s musical score, earning nominations for a variety of awards, taking home the Academy Awards for Best Animated Feature and Best Original Score among many others. Up is also considered one of Pixar’s most heartbreaking movies, and to make it all even sadder, a theory gives a different perspective to Carl’s story, explaining that he wasn’t exactly going to Paradise Falls, but he was actually on his way to heaven.

Why Up Is Considered One Of Pixar's Saddest Movies

Ellie and Carl painting their mailbox

When Up was released, no one expected to get attached to Carl and Ellie so quickly and for Pixar to drop a major bomb during its most beautiful sequence. As mentioned above, viewers meet Carl and Ellie when they’re kids, and Up shows the evolution of their relationship, showing them getting married years later, moving into their first house and renovating it together, working together at a zoo, sharing their dreams and making plans together, though things didn’t always go as they hoped. Carl and Ellie wanted to have kids but couldn’t, which was a big emotional hit for Ellie, but they eventually moved on. Sadly, as Carl got tickets for them to travel to Paradise Falls, Ellie fell sick and passed away, leaving Carl heartbroken and alone. Carl wasn’t the same after Ellie passed away, and Carl became a cranky old man.

Up’s opening sequence was key to the movie’s success and has been pointed out as one of the most beautiful yet heartbreaking moments in cinema. Docter has said the opening sequence was important as viewers needed to love the characters in order to follow them through an adventure like getting a house to float into the sky with balloons, and they needed to give the audience a reason for Carl to do such a crazy thing. With just one sequence in its first minutes, and with a beautiful instrumental piece by Giacchino, Up earned its spot as one of Pixar’s saddest movies.

Up Theory: Carl Died Right After Ellie (& Russell Was Guiding Him To Heaven)

Up house with balloons mr Fredricksen

In case seeing the beginning and end of the relationship between Carl and Ellie wasn’t enough, a theory makes Up even sadder by suggesting Carl also died at the beginning of the movie. The theory, posted on Reddit, explains that Carl died in his sleep the night after the court tells him he needs to move out of his house as he was deemed a public menace after striking a construction worker. What follows, then, is Carl’s journey to heaven, and he’s guided by a very special guardian angel: Russell. The boy explains to Carl that he needs one last badge in order to become a Senior Wilderness Explorer, which according to the theory, actually means that he would finally earn his wings. Russell’s final badge is “Assisting the Elderly”, and he tells Carl he can help him cross the street, the yard, or the porch, but he has to help him cross something, and he does: he helps him cross over into the afterlife. Carl’s house represents his attachment to the physical world and Paradise Falls is how Carl imagines heaven to be, so the house raising and flying away represents Carl’s transition from the physical world to the spiritual one. When he lets go of the house, his transition is complete, and he’s now in heaven ready to reunite with Ellie.

Related: Pixar Movies In Chronological Order (Based On The Pixar Theory)

Of course, the theory has its problems, such as Ellie leaving Carl a letter encouraging him to seek a new adventure, and at the end of Up, he attends Russell’s ceremony and eats ice cream with him, which according to the theory would be Carl returning to Earth after everything he went through to get to heaven. While this theory certainly makes Up a lot sadder, the details playing against it can easily debunk it, but like most theories, it’s up to every viewer to decide if it's possible or not.