frank/karen au where they live in the same apartment/building
Frank moves in literally in the middle of the night. One day the apartment is empty, the next there is someone living in. The other tenants, Karen included, are surprised when suddenly there's a new name on the buzzer and movement coming from the apartment that had been empty for a long time.
Karen keeps odd hours because of her office hours at Nelson and Murdock and notices that often when she's just coming home, Frank is just leaving. She has no idea what he's up to but there's something eerily familiar about him and his stance.
The maintenance guy in the building is Completely Useless and when Karen's air conditioner breaks during a heatwave, she's stuck with the heat in her apartment (and many, many fans). Frank overhears her complaining about it while she's on the phone and once she hangs up, offers to take a look at it. He fixes it within an hour and Karen is so thankful she could probably kiss him. Now if only she could convince him to fix the AC at Nelson and Murdock.
Karen repays Frank with a batch of cookies. They're hard and he can barely bite into them, but he smiles at the box every time he sees it – even if he can't figure out why.
Frank has been keeping a dog in the apartment, even if he's not supposed to. The dog is mostly good at keeping quiet so no one knows until Karen locks herself out of her apartment and knocks on the door to call the landlord. Karen promises to not tell, but keeps the knowledge of the dog to herself in case she needs anything from Frank.
After she finds out about his dog, Frank tells her where he keeps his spare key so she can make sure the dog gets fed when he's gone for longer periods of time (he always finds a way to let her know when it's going to happen).
Each time he comes back after being gone for longer periods of time, he takes her out for breakfast and they talk. It's mostly small talk and they don't talk about anything of real importance (ie: why he's gone all the time, Karen doesn't ask (even though she would love to know.))
When Karen is in his apartment six months after Frank first fixes her AC, there's a sniper on the next building waiting to take a shot on Frank. She notices the laser before he does, and when she points at it, Frank tackles her to the ground while gunshots go off. Even once they stop, Karen is frozen in fear because despite everything that has happened to her, she's never had that many bullets shot at her at once.
Frank doesn't tell her why those people are shooting at him. But he does promise her that he will never let anything happen to her.
send me an kastle au and i’ll give you 5+ headcanons about it