(Y/N) and Sans have been best friends for who knows how long. Nothing could ever ruin their friendship... or could there be something? The human and monster war breaks out and the monsters are trapped underground, making Sans and (Y/N)'s friendship come apart. Years later, (Y/N) decides to hike up Mt. Ebott, where the monsters got trapped under, and falls down a hole. They end up seeing everyone they remember from when they were younger, but will THEY remember (Y/N). If they do, will they even protect her from the evil in the Underground, or will they let her die?