Papyrus sighed as he watched the blizzard occurring outside his window. He squinted, trying to see through the endless barrage of snowflakes for a familiar, short, black and red figure walking back to the house. He had ordered it... or him, to kill that filthy human. "WHERE IS THAT BONEHEAD?" Papyrus thought to himself, glancing at the grandfather clock in the living room. Almost 12 o'clock. "HE SHOULD HAVE BEEN BACK AN HOUR AGO..." the skeleton murmured.
That 'bonehead' was Sans, his only brother. Both had grown up without parents, and... according to Sans they had been abandoned, as Papyrus didn't remember it well for some reason. As Papyrus and Sans grew up, Sans ended up being short while Papyrus got tall, despite being the younger brother. Sans was also weak, having only 1 hp. Papyrus had threatened him with that in mind, and so Sans had been trying to please or at most impress Papyrus, trying to prove he wasn't so weak. Sans also seemed to be afraid of him...
Suddenly Papyrus was startled by the creak of the door opening, followed by a gust of wind and snow, and weak footsteps. He turned to see Sans sweating a LOT (though with them being skeletons it was unknown why they can sweat, along with a bunch of other things). He also seemed to be hiding something with his coat's sleeve, where his rib cage would be, if they weren't wearing clothes.
"h-hey bro..." Sans said weakly, leaning against the door with his other arm.
"SANS, WHERE HAVE YOU BEEN?! YOU SHOULD HAVE BEEN HERE-" but Papyrus's voice cut off when his brother began to fall over, before the taller skeleton caught him in their arms.
"SANS, WHAT ARE YOU-" Papyrus started to say, but stopped, as he saw his brother's teeth clenched in pain; his eye sockets struggling to stay open.
"BROTHER...?" Papyrus's face changed from a look of confusion into shock, as he had moved Sans's arm away from his chest to see that his shirt had a huge gash across it, with blood seeping out of a wound.
"WHO DID THIS TO YOU...?" Papyrus mumbled, his eye socket starting to glow red.

Sans tried to open his eye sockets, but everything was fuzzy.
"p-papyrus?"
Sans's eyesight slowly got less and less fuzzy until he could see everything clearly. He saw Papyrus sitting in a chair, with their hand on their face, with him turned so that Sans could only see the right side of him. He seemed to be deep in thought.
Sans sat up quickly in what seemed to be Papyrus's bed, checking for a wound on his chest.
No wound.
He sighed in relief. "it was only a nightmare..." he thought, but opened his eyes to see that Papyrus had turned to face him, with blood smeared all over his left side. "or not."
"p-papyrus! i'm so sorr-"
"IT'S OK. YOU DID YOUR BEST. I'M PROUD OF YOU FOR THAT."
Papyrus then grabbed his boney hand, smearing blood on it. Sans looked shocked at first, but then he smiled the first genuine smile he'd had in years.
"thanks bro."