A/N) Look - a chapter! This is short, but it exists. And it isn't even an April Fools, I'm happy to say :P
Quirks
There have been many occasions in which Nick has hated Katherine.
Now hate may be a strong word, but there have been many occasions to merit it, if Nick's being honest. Whether they're throwing their typical banter across at each other or face to face yelling at each other - either is equally probable at any one moment if you leave Nick and Katherine in a room together - sometimes Nick genuinely feels hatred for the callous, insensitive and often utterly infuriating woman that he has worked alongside for the last couple of years.
He does have reason for it, to be fair. The amount of times that Katherine has betrayed, undermined or generally exasperated him could be counted on about a million hands. It's only got worse since she was demoted from CEO – he can now add bitterness to the list of her objectionable qualities.
So Nick has never and probably will never understand why sometimes he finds a tiny smile creeping across his face when looking at her.
Sometimes he notices these tiny traits in the most inexplicable of situations. When there's that familiar glint in her sky-blue eyes, often connoting pride in what new device they've created. When they're hurrying through Calimov in search of some component or machine to aid them in their research and Katherine's dark brown hair is unkempt and falling across her face in their rush to get wherever they're going. When both he and Katherine are called in at a weekend and Katherine hasn't had the time or the effort to put on whatever constitutes her usual immaculate style, so he finds her in jeans or a thick hoodie that usually he could never otherwise picture her in. Whereas you'd expect her to look her best when she wore her typical dresses or smart suits – Nick finds himself unable to look away from her when Katherine's hair is up in a scruffy ponytail, her face bare without makeup. She looks softer, almost. Less severe, less unapproachable. More human.
When Katherine's stressed (which they both are quite frequently in their line of work), he has come to notice the very specific flush that colours her cheeks as she races around the lab shouting at various unlucky technicians who accidentally get in her way. The tone of her voice raises to almost screeching pitches, causing Nick and others to wince and roll their eyes at each other. Now she's just another employee, she doesn't have that same authority to stride around yelling at people, but he still sees that same flush stealing up her face when failing to express any silent anger that boils her insides.
And on the rare occasions that he catches his co-worker off guard in a momentary snapshot of peace that is usually so unattainable, Nick finds himself noticing all these little quirks at once about Katherine, much as he may try in vain to ignore them.