"Yep. Elves that are half-human look like human young adults."

("Like me," he doesn't add.)

"Are you telling me humans and elves are interfertile?" How did they even find that out--nope, not asking that, super not asking that, Bruce was not in fact raised in a barn.

"Yes. And they produce fertile offspring. --We are magic."

"That is--still extremely weird but I guess with you being a designed species it's only on the same tier of weird as everything else going on. Wait, if half-elves are magic and live longer than humans then--never mind. So what are all these folks working on, anyway?"

"Planning the elven economy, assigning presents to children, figuring out who's naughty and nice, learning about what the new Christmas spirit is so we can change ourselves appropriately..."

"I really hope 'change ourselves' isn't as ominous for you as it sounds to me?"

"Well, for one thing we'll have to redecorate all our houses..."

"Huh. Change them how? I don't know my subconscious opinions on Christmas decorations beyond 'lots of lights is awesomesauce'."

"We don't know, that's why we need to learn what Christmas is." He flags down an elf who looks to be about seven. "Can you take us to the Christmas spirit room?"

"Yes, sir," the elf chirps.

Bruce is so! Excited! And nervous! And excited! He's going to see what he did to the Christmas Spirit! If it's good it's going to be awesome and if it's not good that means his brain has a big ole contradiction in it and it could be screwing things up for people even without him acting on it at all! It's like the feeling of being about to get his grades back on a really important test except he has no memory of taking the test and no sense of whether he did well or badly and no idea how high a score is passing or whether there was any extra credit! His legs follow Lev and the other elf without any supervision on his part.

Bruce enters a brightly colored room full of flashing lights and big red buttons and, in general, a child's idea of what a command center would be like, if the child also thought that everything should be decorated with candy canes.

Time to try to read all the labels on all the buttons and switches and lights! If it's anything like being in an airplane cockpit he's likely to end up less with useful knowledge than with a map of his ignorance, but knowing that doesn't make compulsory label-reading less appealing.

The buttons are labeled things like HO HO HO and HALLMARK MOVIE INDEX and HOLIDAY COOKIE MONITOR and TERRIBLE CHRISTMAS PARTY ADJUSTMENTS.

"This is incredibly cool. So, what sort of changes are you seeing so far?"

"We seem to have developed... taste-equivalent vegan eggnog? Do you have any idea what is up with that."

Embarrassed snort of laughter! "Uh. I have kind of been wanting vegan eggnog every Christmas for several years now. And I guess it. Picked up on that." On the one hand, what a frivolous use of magic. On the other hand, maybe people will consume fewer eggs. Also maybe he will be able to get some of the eggnog later.

"An executive got a brilliant new idea for a story about three children investigating whether Santa Claus is real... uh, cultivated-meat turkey?"

"Wow, apparently my subconscious believes that the true meaning of Christmas is having as many different kinds of food as possible. Also that movie sounds adorable."

"As many different kinds of... food without animals?"

Oh, boy. "So, uh, I don't know what the Elven food production situation is or how much you know about how humans do it, but, uh, I don't like--the way humans farm animals is kind of awful for the animals so I only eat plants."

It occurs to him to wonder if the flying reindeer can talk like they do in the movies, though probably it doesn't have any implications for nonmagical animal cognition either way.

"All our food spontaneously comes into existence through magic. We thought that the animals were happy and lived on farms with cheerful farmers in overalls, as depicted in children's media?"

"Spontaneous magic food is awesome and I'm sorry human media is full of lies."

"Oh. I'm-- glad you're doing something about that?"

"Thanks. It--makes sense, the more I think about it." Also it is belatedly occurring to him that while he's here he can eat anything (that isn't someone else's) without having to investigate it, and that in itself is extremely Christmas. 

"So what's next on the agenda?"

"Explaining things to your family? Listening to me talk about my fifty years of work on what we should do with presents?"