Nightmare Under Universe
Steven and his friends (Pearl, Sans, Frisk, and Peridot) had met with a three dress up kids who turn out to be working for an evil monster in Halloween Town, Oogie Boogie. With that the four ended up in a town call Halloween Town meeting the Pumpkin King, Jack Skellington, and his whole family with a good friend of Jack's son Friday.
Would the four ever make it back home or would they be trap in Halloween Town?
Read and Find Out!