You see Papyrus at the end of snowdin, which was a ghost town due to Sans' unexpected genocide. Papyrus was on his knees, beside Sans' torn jacket. He was muttering quietly to himself.

"No... No no no...! Sans... I did this... I killed my brother! This is ALL MY FAULT!!!"

Papyrus continued saying this... Until he stood up and slowly shook his head.

"... It's... Not my fault. I was only defending myself, and Sans only did this to fight the human. It's... The human's fault."

Papyrus turns around and you see his eyelights shrink down when he saw you.

"... Speak of the devil..."