Christmas midnight: the door to the supply closet bangs open, and Santa finds Alovus and Mioryu vainly trying to fit Mjölnir into a production cabinet.
"Okay kids, I appreciate the work you did here, but stop being stupid. It's time for you to get back on your airship and go home."
"We know what you did!" Mioryu shouts. "Those kids weren't supposed to be on the nice list at all, they were the naughtiest of the lot, and you had us make fireworks for them!"
"What?! That's not true at all -- I checked the list twice!"
They are interrupted by a clattering of hooves, and a blinding red glow appears in the doorway.
"Rudolph?" Santa asks. "Why are you in the workshop? And do none of my locks work?"
"Ho ho ho, motherfucker." Rudolph says. "Look who's laughing now. That's right, I put those naughty kids on the nice list. I was tired of hauling tons of coal every year and in a few hours those kids are going to be waking up to find a highly explosive production cabinet that produces six sets of fireworks before breaking down. They're going to blow up their houses and then they won't have a chimney to deliver to!"
Alovus jumped in: "Well jokes on you, because we figured out your plan! I mean, we thought it was Santa's plan, but still. Those production cabinets don't make fireworks at all."
"Wait, what do they make?" Santa asked.
"N-o-thing." stammered Mioryu. "I mean, they make fireworks, but like really weak ones. No blowing up a house with them. Anyhow we need to go catch that airship. Byeeee!"
One week later, Alovus and Mioryu are headed to the university New Year's Eve party. Around them kids were running up and down the street with snap sticks and poppers causing all sorts of mischief. The more precocious kids had figured out how to use them to make miniature Thor's hammers and were shooting sparks of lightning at the others.
"Good work figuring out those kids were naughty, that would have been a disaster." Mioryu said.
"Well, good work figuring out the recipe for Thor's hammer!" Alovus laughed. "So, it seems we got a Christmas card in the mail, want to see?"
Santa writes: "Thanks kids for all the good work you did with us. Not sure what you really did with those alchemy cabinets but I hope you got something useful out of it. Thanks for saving Christmas, good luck with school... and Merry Christmas!"