"This is stupid, why are we here again?" Undyne asked.
"W-well, th-the papers from those books that I w-was reading said that Sam and Dean lived here…." Said Alphys embarrassed.
"You big dork." Despite the harsh words, they were said with nothing but fondness.
The taller of the two monsters broke down the door to the bunker and a yelp was heard from upstairs as the Winchesters ran down to see what treat they now had to face.
Almost immediately Alphys started fangirling.
"OH MY GOSH ITS SAM AND DEAN AND THEYRE REAL AND HERE AND I CANT BELIEVE YOU SAVED THE WORLD AND DIED A BUNCH AND OH MY GOSH!" she started hyperventilating and passed out right in the middle you the library.
"WHAT DID YOU NERDS DO TO HER IF SHES HURT I SWEAR-wait is that a 9mm Taurus?" Undyne asked looking at the gun Sam held in front of himself while Dean had a sword.
"Ummmmmmmmmm yeah?" Sam said a bit hesitantly.
Then Undyne started fangirling.
"IF YOU SHOW ME HOW IT WORKS BEFORE I KILL YOU ILL MAKE IT SLOW AND PAINLESS!"
Alphys woke up with a huge grin on her face at meeting her favorite characters.
"So how do you know about us exactly?" Dean asked.
"W-well sometimes these papers would wash down in the dump that talked about your life and it had your adventures and address and everything!" Alphys explained.
Sam and Dean looked at each other and said simultaneously with a groan "Chuck."
"So they're not dangerous?" Undyne asked.
"Th-they are b-but not to good guys."
"Oh…. Well in that case, HUMAN, I DEMAND TO SPAR WITH YOU!"
And so it began.
Twelve hours later, the bunker was a total mess, everyone was slightly singed from the science experiment that Sam and Alphys did, and everyone but Alphys was bloody and bruised from both Undyne fighting them and Alphys gloomping them.