Why is it that animated movies are so good at making audiences feel things, especially sadness after a character loss? There are loads of animated Disney movies out there that will have viewers sobbing like babies by the end of them, but Pixar's film Up decides to slap people in the face with emotions right within the opening scene. Movie fans kind of have to applaud the creators of a movie for being able to make millions of people weep about characters they've only just met, but even more credit should be given when it is all done in one montage scene with little to no speaking.
This fan theory From Reddit user bubonis suggests that Ellie wasn't the only character to die within the opening act. Carl and Ellie met when they were only small children who both idolized the explorer Charles F. Muntz. Their dreams were to be the greatest explorers and fly to Paradise Falls. They have a classic Disney fairytale romance as the two grow up together, have all the same interests, and fall in love. But things take a darker turn (a common animated Disney movie trope) when Carl and Ellie find out they can't have children. However, they still keep their promise to each other to one day make it to Paradise Falls.
But life happens, and the two have to constantly use the Paradise Falls vacation money they have been saving for more practical expenses and emergencies. They still have a happy and long life together, but they get older and older without fulfilling their dream. That is until one day, Carl finally is able to arrange the trip. Before they can go, Ellie gets sick and dies. More cynical viewers have often said that the message behind this movie perpetuates the idea that a person can't get out and travel until their spouse dies, but others have a more spiritual take away from the 2009 film.
Carl and Ellie were both very old. When Ellie dies, Carl is broken-hearted. In real life, when two people have been together for a very long time and are both nearing the end of their lives, when one spouse dies, the other shortly follows. Many have said this is due to a broken heart. This can even be seen in two animals who are close to one another—if one dies, the other might also die from loneliness. Whether it be from a broken heart, old age, or a combination of the two, some fans believe that Carl actually is dead the majority of the film, and that the young "Wilderness Explorer" named Russell is really an angel sent to guide Carl to the real Paradise Falls (or the afterlife).
During the first act of Up, Carl gets into an altercation where he accidentally assaults someone out of anger for them trying to take Carl's house away from him (his last connection to Ellie and their life together). He is sent to court, where he is ordered to move into a retirement home. The day the caretakers come to take Carl away, viewers see Carl escape with his entire house thanks to a few million helium balloons. His goal is to get himself and the house (which he refers to as Ellie) to his idealized Paradise Falls. But in the theory, Carl actually died in his sleep on the night before he was supposed to be taken away, and this is actually a story about his journey to the afterlife.
In the movie, Russell is presented as a young Wilderness Explorer trying to earn his last badge—which is an Assisting the Elderly badge—so he can become a senior explorer. Many are interpreting this as him trying to earn his wings as an angel. And, the house might also be a representation of Carl's physical attachment to his life and the world, and Carl has to find a way to let go of his attachment to the past. In the film, Carl refuses to give up his house—toting it around, tirelessly holding on to it at all costs. That is until the end, where he finally lets go of the house and follows Russell into an afterlife that looks a lot different than he and Ellie imagined it would look.
No one can truly know what the afterlife holds, and Paradise Falls is only Carl and Ellie's interpretation of what heaven might have been. When he lets go out the house, he lets go of his ties to Ellie and his life, and when he leaves Paradise Falls, he leaves behind his idea of what heaven would have been. He is now free to travel into the afterlife, free of all anger and regret. The afterlife appears to be quite similar to real life, only now Carl has some company in Russell. Perhaps he may even be reunited with Ellie.