The small metal cylinder in his hands is not perfect, yet. He needs to use the micro sander, needs to ensure that the delivery system will work properly, not just properly, perfectly, the way everything he works on is perfect. He examines it from each side, and smiles. Done. He turns and knocks on the glass, and shows it to her for recognition, approval of a job well done. And that turn takes a thousand years, a millennium, the entire action slowing through muddled time because it is so wrong. The feel of the glass as he raps it, the barrier between them that is less than an inch thick but has never been there before. And he can't cross it. She gives him a small smile, and he feels a lump rising at the back of his throat, which makes him turn away again and carry on with something he can change. The only way he can help.

When Coulson came into the break room, Fitz knew something was wrong. Coulson had this way of looking at people when he had bad news to deliver, this softness around his eyes, and he was staring at Leo with that soft, soft look. It made his insides shock, and all he could remember, right then, was Gemma and the noise of surprise she made earlier when she- And he knew.

"No," he said flatly, quietly, and Skye raised an eyebrow, before turning to look at Coulson.

"What's up AC?" she asked, and Fitz felt himself start to stand up, because Coulson was still staring at him, and Jemma had been shocked by the floating man in the woods, the man with a virus, and every virus needed to be able to transmit itself somehow, and this wasn't happening.

"We've got some time," Coulson started, and now Ward looked around, alert. This made Fitz feel worse. Because it was happening, and it was serious. "Simmons has been infected by the virus. I've quarantined her in the lab-"

And that was exactly all Leo could listen to before he needed to see her. He walked, then he ran, and he burst into the cargo bay. She was sitting on the floor with her back to the glass wall of the lab, and he didn't say anything. Instead, he walked to the glass and looked down at the top of her head for a moment. Her hands were neatly clasped in her lap, and he could see how white her knuckles were. He turned around and leant against the wall, letting himself slide down to the floor.

"I'm feeling a little bit under the weather Fitzy," she said, very quietly. His lips curved into a small smile which quickly faded.

"I can make a device to deliver the vaccine-" he started and she interrupted him.

"It's technically an anti-serum-"

"I'm an engineer, it's technically not my field-"

"That doesn't mean you can't use the correct terminology-"

"Oh, I can use it, yes, I can, maybe I'm just choosing not to-"

"Hardly a reassuring attitude when I need you to be precise-"

"I need you to stop arguing with me about semantics and give me the parameters-"

"Fitz it isn't semantics – oh just come to the hatch!" She finished, annoyed, and he frowned and jumped up. Anti-serum, honestly. As he turned and waited at the hatch, he watched her crashing around at the back of the lab, throwing various tools and materials into a plastic tray. She worked quickly, movements smooth and measured as always. He drummed his fingers impatiently against the wall, and saw her shoulders stiffen slightly.

"Will you please stop that incessant rapping, I'm going as quickly as I can-"

"I can see that, I just hope you haven't forgotten anything, left the micro sander-"

"I've got the bloody micro sander thankyou very much, which by the way I saw you using-"

"That was an invasion of privacy I don't ever want to be repeated, a man should be able to-"

"Sand down his own toenails using a piece of equipment that cost thousands of dollars-"

Then she turns around, and he sees her face, and he sees her pale, clammy, shadows under bright eyes. Sees the smallest shake in her hands as she takes a breath then walks towards him and places the tray on the shelf. She won't meet his eyes, and he can't move his eyes away. He opens the hatch and removes the tray. Everything he could ever need, all in one place.

"Jemma-" he starts, quietly, and then she does look at him directly, and he feels his grip around the tray tighten. Something he can do.

"Yes?"

"I'll get started," he says. She nods once, and they both move to the wall, both slide back down to the floor. He can almost feel the heat from her back through the glass, an idea which he knows is impossible, heat from a human body can't possibly transfer through glass that quickly. So he is imagining it. And if he can't make the device, can't make it work, can't make it perfect, then he'll be imagining her, for the rest of his life, and that is unimaginable. Unacceptable. He'll always be sitting with his back to some glass wall, unable to see her though she is so very close. So he sorts through the tray, and he starts to work.