Interstellar travel had a complicated ending that required a certain amount of scientific knowledge and cultural background to understand. At the end of the movie, humans successfully passed through the wormhole and arrived in another galaxy. However, when they returned to Earth, they found that the Earth's environment had undergone tremendous changes, and humans could not survive. In order to solve this problem, humans decided to head to that galaxy to find a new planet to live on. During this process, scientists constantly explored new universes in search of planets that could help humans survive. In the end, humans successfully found a habitable planet and brought it back to Earth. However, the environment on this planet was also very harsh. Humans needed to constantly transform in order to survive. The ending of the whole story was that humans finally found a way to survive and find a way forward through constant exploration and adventure.