SHIELD was a pretty no-nonsense place. If you wanted great work hours and holiday parties you could go work for Albertson's.
This said, SHIELD didn't put much into the way of decorations.
There was a little tree in the break room, and someone had put candy canes into the staff cupboard. That was it, really.
The agents didn't give much thought to the holiday, other than to dread the kind of tricks the supervillains would decide to get up to.
That was, until the Avengers showed up.
No one knew how, but within a day of the Avengers' first visit to SHIELD in the month, everything changed.
Everything.
The next day, the agents showed up to work to find everything…
Well, Christmasified was the best word for it.
Although SHIELD had the best security in the world, the six superheroes managed to sneak in, avoid the night staff, and sneak out within half an hour.
Oh yeah, and they also decorated.
No matter where you looked, there was something Christmas themed.
One agent went to the restroom only to find the toilet waters green and red alternating in each stall.
Another rookie found every gun in the arsenal equipped with a little, smiling Santa sticker.
If you turned the mugs in the break room upside-down, you could find a little jingle bell.
Someone said that they even saw Fury angrily trying to yank an ugly Avengers-themed Christmas sweater off his head.
No one checked, though.
Come to find out, the group of superheroes had been...displeased when they found out that SHIELD didn't do Christmas.
For the next week, the intercom speakers were blasted by "It's Beginning to Look a Lot Like Christmas" every time they tried to remove a decoration.
Eventually, they just stopped trying.
No one tried to argue that the shiny gold, red, and green tinsel decorating the place made it less sneaky.
It wasn't hard to find SHIELD, really.
Some thought that attacks on base had actually gone down since Christmas had puked all over headquarters.
Maybe it was because the villains were too busy laughing about it to actually attack.
However, when Hawkeye and Captain America visited the SHIELD coffee shop only to find a new selection of holiday themed drinks, the two superheroes looked so smug that Agent Peters, who had been sitting nearby with a bell-adorned elf hat, had laughed so hard the whole base could hear the bells ringing.
And all the agents found they didn't mind "It's Beginning to Look a Lot Like Christmas" so much anymore.