"I'm so sorry, Jemma."

He tries to smile at her. He tries to act like nothing is wrong. He tries to appear completely normal. He tries, tries, tries. He won't apologize to her like Coulson did. But everytime he taps on the glass to get her attention, to show the progress he's making on his end of the work, it feels wrong. The muscles on his face are too tight from smiling at her. There's a pain behind his eyes that makes him feel like his head will split open at any bloody moment. And there's this compression happening somewhere in the vicinity of his lungs, like someone is pounding on his chest with the hammer of a Norse god. Every so often, he forgets how to breathe.

Breathe.

He doesn't know why this has never occurred to him before. That she would be the one to be somehow damaged by being in the field. She's always been the more adventurous, the more courageous of the two of them. She's always been more. She's the one who wanted to go into the field. She's the one who convinced him real SHIELD world experience was better than being stuck in some classified basement laboratory, that they would be able to do real good, make important discoveries even. He always thought it would be dangerous. He always thought there was a chance-

But he never thought it would be her.

If anything, he thought their roles would have been reversed somehow. That she would be the one standing out here while he was quarantined away. He thought that she would be the one fighting to keep him smiling, keep him fighting, keep him thinking. Not the other way around. He doesn't like this quiet Jemma. This woman who barely bickers, whose words are so soft he has to strain to hear them. He doesn't like that she's not thinking through her attempts at a vaccine (anti-serum, he knows) aloud. He's so used to being her sounding board, to finishing her thoughts before she has a chance to think them, that he doesn't know where to let his own thoughts run to now, other than a flash of light and a floating Jemma in the middle of the lab. It's something he can't unsee, no matter how hard he tries, and it hasn't even happened yet.

When he finally does get her to yell at him, even just a little bit, it hits him - this could be the very last time they do this. Whatever this is. This back and forth. This strange give and take they have. And he is very much not okay with that. He cannot get air. He cannot make his lungs work right. And he can't stop the tears from coming to his eyes.

"You have to fix this."

"I don't know how."

And he doesn't accept that. Because standing in front of him is Jemma Simmons, one of the greatest minds that has ever worked for SHIELD, other than him, of course. She can fix anything. That's what she does. She's even, maybe, been fixing him. And he didn't even know he was broken. He doesn't acknowledge that solitary tear trickling its way down his cheek, and wisely, neither does she. Instead, they do what they do best - they focus on the problem, and they work together, quarantine be damned, to fix it.

He doesn't get to see her right away when she and Ward are able to get back on board the plane. Agent May warns he and Skye to stay out of the way. To give Coulson his space. To let them all adjust to what just happened. And when Skye finally goes to make sure Jemma is alright, he doesn't move. He finds that he can't make his legs bend to walk across the floor. He sits on the bed, pillow clutched to his chest, watching her fall into the clouds over and over again, like the film stuck in a 1960s projector. Like his earlier image of her floating in the middle of the lab, he cannot unsee it. There's a hopelessness on her face that he never wanted to witness. And that's something he can't shake. Jemma Simmons isn't someone who has given up a day in her life. But she did. To save them all.

And she's falling, falling, falling.

He also can't wrap his head around the fact that the screams that came from the lab originated from his mouth. He's never sounded like that before. He never wants to again. He never wants to feel the way watching her standing on the cargo door with tears running down her face made him feel.

He just screams and screams.

Instead of going to find her, he closes his eyes, and sighs.

She comes to him after being reprimanded by Coulson, eyes no longer red rimmed, skin no longer clammy from the alien virus. And he wants to tell her - well, he actually isn't sure what he wants to tell her. He just wants her to know that he tried to go after her, that he couldn't imagine being on this plane, working in his lab - their lab - without her.

"Fitz?"

It almost doesn't register that she's asking to come in. But he nods his head and clutches the pillow tighter to his chest, not moving from his spot on the bed. He clutches it tighter, Too tight. His knuckles turn white. When she takes her seat next to him, he feels every inch of her that's pressed against his side. He can't make himself move away. He's used to them running into one another in the lab, there only being so much room. He's used to their heads bumping when they lean over a petri dish. He's even used to their arms resting against one another when working on a particularly difficult task. And now that she's next to him again, he's aware of how empty the room feels when she isn't there. How utterly wrong it was to work with her while she was infected and not be able to tap her on the shoulder or touch the back of her hand.

When he finally begins speaking, he babbles almost incoherently about what happened. She calls him a hero. And he doesn't understand why. What he did wasn't heroic. If anything, it showed just how truly scared he was to be here alone that he was willing to risk his life to keep her here with him.

She kisses him on the cheek following her proclamation of his heroism. And he doesn't understand why. He doesn't say anything else as she leaves, but that compression in his chest speaks to him again. It moves from his lungs to his heart. And again, he forgets how to breathe. He pulls the pillow in close to him, fingers clenching and unclenching the fabric as he forces his lungs to expand and contract.

A/N: It has been such a long time since I've posted anything on here! This was a result of a fifteen minute challenge for the word breathe that may have turned into a 25 minute challenge because I stop and start a lot as I write. I, as a general rule, don't write fanfiction for anything in the Whedon-verse. I feel like it's all so well done as it is, I never have the urge to put my own stamp on it. But when I was experiencing some writer's block on another story last night, the most recent episode of the show was fresh in my mind, and this happened. Hope you liked it!