A long time ago there was a war between human and monsters. The humans won and sent the monsters underground and sealing it with a barrier created by wizards. Ever since then they have been trying to get out, the monsters go to drastic measures in order to break the barrier.
Dr Gaster created two clones of himself for an experiment. He cut out holes in both of his hands and used them to create skeletal figures. He named them Sans and Papyrus. He didn't know what to expect from the two creations and he wasn't so surprised that they didn't move at all. After a couple hours they were starting to move and look around. Sans looked at Papyrus and just stared. They stared into each other's eyes, Papyrus stood up and approaches him, Sans backed away as he was afraid and Papyrus sat down. He smiled and got a little closer, this time Sans was less afraid and fully turned so his whole body was facing him. Papyrus scooted closer and closer until his face was an inch apart from his.