One day, Smg4 goes on hiking trip with his friends and Mario bets that he's too scared to jump down a strange hole in the mountain. An unfortunate accident happens and Smg4 gets stuck in a new world that has copies of his friends, except they don't seem to know him. For some reason they keep calling him "the pure soul" that is needed to finally escape. A new adventure begins to escape the underground and maybe make some new...old friends?