Fitz looked up from his work, an unexpected feeling of dread settling into the pit of his stomach. He didn't quite understand why he felt so panicked all of a sudden. Granted, it might have had something to do with the fact that his expertise had been barely required in months, or that he still wasn't certain how useful he would actually be in his current circumstances. Then again, perhaps his anxiety stemmed from the alcohol that his system hadn't quite gotten rid of, or from his severe lack of sleep. Or perhaps, when it really boiled down to it, it was the prospect of working with Jemma again that was the problem.

Maybe the source of Fitz's sudden panic wasn't a complete mystery to him after all.

Despite his reservations, Fitz still wanted to help as much as he could. He gently set the prototype down on the desk before getting out of his seat. "What…what do you need, sir?" he asked, making his way over to the front of the lab. He could feel Jemma's eyes boring into the side of his face, so he made sure to keep his gaze set on Coulson.

Coulson lifted up a large containment case and set it on Jemma's lab bench. "Our agents picked this up over in Bruges," he explained, inputting a complicated security code into the side panel. "We swept the place for more, but this is all that was left." As he unclasped the case, Fitz held his breath, expecting some kind of energy emission or strange noise or flashing lights. And while the small disc-like shape situated in the middle of the case didn't demonstrate any of those things, the dread in Fitz's stomach failed to disappear.

Jemma inched forward to inspect the object, and Fitz had to restrain himself from holding out his arm to stop her. "Is that…" she began in a murmur. "Is that one of the weapons-"

"That HYDRA's been using to disintegrate some of my best agents?" Coulson finished for her, placing one hand on the lid of the case and looking at its contents with disgust. "Yeah," he nodded. "And it's really starting to piss me off, almost as much as the name. HYDRA's calling them Splinter Bombs."

Fitz instinctively glanced over at Jemma, who had an all-too familiar look on her face. "Oh, well that'd be because of-"

"Yeah, how it-"

"Burrows under the skin, which can cause an infection-"

"And that can, er…migrate to other parts of the body-"

"Yes, exactly," she agreed. "If left untreated, splinters can cause severe internal-"

"Damage, yeah. Yeah, that's…that's quite-"

"A clever name, really," Jemma murmured before catching herself, probably noticing Coulson's very un-amused expression. "But terrible, utterly repulsive-"

"Horrible, yeah," Fitz quickly muttered in agreement. "Really bad taste, that is."

There were a few moments of awkward silence as the weight of what they were facing descended upon them again. It wasn't that he'd forgotten the destructive nature of the weapons in question, or that he still didn't feel ill just thinking about those agents that had died because of his insufficiency. It was that for a second, for just a second, everything seemed normal again. For just a second, he and Jemma were finishing each other's sentences. For just a second, he and Jemma were marveling over the terrible beauty of scientific advancement together like they used to, like they'd done every day since they'd met each other at the Academy. For just a second, they were simply FitzSimmons again.

But as quickly as the moment had come, it was gone. And Fitz knew that whatever happened between them, things could never return to normal again. There was too much there, too many reminders of how much things had changed.

Fitz folded his left arm underneath his right to keep from fidgeting. He cleared his throat. "And…and what exactly did you have in mind for-"

"You want us to reverse engineer it, don't you?" Jemma asked, her eyes still transfixed on the weapon. Fitz was too distracted by the fear in her voice to care that she'd interrupted him.

Coulson nodded again. "The only thing that's been getting under my skin is how HYDRA has managed to stay one step ahead of us this whole time," he said. "This could give us a way to level the playing field."

"But sir," Jemma argued cautiously. "These aren't just ordinary weapons. They've been developed because HYDRA has somehow found a way to weaponize the effects of-"

"The Obelisk," Coulson finished, his mouth in a thin line. "I know. And that is precisely why I need you two to figure these things out. If HYDRA's got the Obelisk, we need to learn as much as we can about it if we're gonna stop them from unleashing any more destruction." He glanced over at Jemma, and he must have noticed how pale her face was, because his voice was much gentler when he spoke again. "You've been in there, Simmons," he said quietly. "You know that if HYDRA has the Obelisk-"

"Then these Splinter Bombs are only the beginning," she nodded, a rare expression of hatred passing over her face. It was gone in a second, but Fitz saw it, and he had to dig his heels into the ground to keep himself from stepping closer to her.

Since she'd returned, Jemma hadn't spoken to him about her time at HYDRA. But the way her voice hardened at its mention and the tears that she quickly blinked away convinced him that every single terrible thing he could possibly think of had happened.

He still couldn't even contemplate the reality of her being there, of her voluntarily going into that hellhole, without feeling sick to his stomach. It was enough to drive him mad if he thought about it too much.

Fitz clenched his fist under his right arm and tried to focus on the conversation.

"Exactly," Coulson continued. "We don't know what HYDRA has planned, but I'd put a lot of money on it not being good. We need to be ready for whatever they throw at us." He glanced down at the small disc, not even bothering to crack a smile at his own pun. In fact, he looked more tired than Fitz had ever seen him. "We can't afford another attack like this, guys," he finished quietly. "I can't afford to lose any more agents."

"We'll get right on it, sir," Jemma assured him, her voice reflecting a certainty Fitz knew she didn't have. "But the hard drive I brought from Whitehall's lab contains no references to the Obelisk or these Splinter Bombs. We'll have to deal with the weapon directly if we're to reverse engineer it."

"Do whatever you have to," Coulson ordered, looking over at Fitz. "I trust that you guys know what you're doing."

Fitz had no idea why Coulson had such unwavering faith in their ability (or, perhaps more specifically, his ability), but he didn't argue. "Got it, sir," he said softly.

Coulson gave him a curt nod before gesturing to one of the other agents that had entered the lab. "The D.W.A.R.F.s did a general scan of the safe house, so whatever they picked up might be able to help you."

Fitz stepped forward to take the bots' case out of the agent's hands, and carefully set it down on an empty table. He bit back his irritated comments about how only two of the D.W.A.R.F.s had been returned to their designated places, deciding to save them for another time. But he would definitely be giving a very detailed presentation on how to properly handle the drones in the near future.

"Sir," Jemma continued, just as Coulson was about to head out the door. He spun around, his forehead creased in confusion. "Agent Walters," Jemma clarified, sounding hesitant. "Do we have any…" Her voice faded away, and she looked only somewhat relieved when Coulson seemed to know what she was asking.

"There wasn't anything left to bring back," Coulson said after a pause. Fitz felt the pit in his stomach grow, and he knew he wasn't going to feel like eating anything for a while. Jemma didn't look like she was faring much better, and not just because she wouldn't have any tissue samples to work with.

"We've got the security tapes from the safe house, and from the attack on the UN," Coulson went on. "Use those. I'm telling you, whatever you can find out about these things, or about the Obelisk, or about how to keep any more S.H.I.E.L.D. agents from turning into dust, will be a hell of a lot better than what we've got right now."

"Understood, sir," Jemma replied, giving him a tight smile that disappeared as soon as he was out the door. She and Fitz stood in front of the lab bench for a few more seconds, but Fitz didn't quite know where to start. Usually he and Jemma were able to jump in on a project immediately, easily assessing what needed to be done and barely even needing to speak in order to understand each other. But things were different now. Now he had no bloody idea what Jemma was thinking.

In the end, Fitz decided that scanning the weapon for its properties would be as good a place to start as any. Unfortunately, though, Jemma must have had a similar thought, because just as he stepped towards the table, she moved at the same time.

"Oh! Sorry. I'll just-"

"Yeah, I was just-"

"Going to get the-"

"And I was just gonna-"

"So if you want to do that, I can-"

"Yeah, yeah, go ahead-"

"I'll just download the information from the D.W.A.R.F.s-"

"And, um…I'll just take care of this, I suppose-"

"Right."

"Yeah."

Jemma carefully stepped past Fitz to grab the case, and Fitz rested his hands on his waist until she'd taken the D.W.A.R.F.s over to her workstation. If Fitz hadn't been so nervous about the task at hand, he might have laughed at how similar the exchange had been to their first day working together. At least now they had a little more room to work with, instead of that small fume cupboard they'd been cramped in.

But then again, at least that day she'd tiptoed around him out of disdain instead of pity.

Fitz tried to push his distracting thoughts aside. The last thing he could afford right now was to be unfocused. There was a deadly weapon derived from alien technology not two feet in front of him, and Coulson needed them to determine how it worked in order to prevent the loss of countless lives as well as possible mass destruction.

Fitz should have known it was never going to be easy. Sure, it was his first real task since that cloaking disaster. But working with S.H.I.E.L.D. (and specifically for Coulson) had never been a walk in the park.

After examining the weapon for a couple minutes, he retrieved his tablet from his desk and borrowed Sleepy to check for radionuclides. As the bot whirred back and forth, Fitz snuck a glance over at Jemma, who was studiously examining the information from the D.W.A.R.F.s on her computer screen.

"I'm afraid this isn't going to give us much," she murmured, shaking her head. "The drones barely picked up any residual effects from the weapons at the safe house. No radiation, no abnormal electrical activity, not even an anomalous speck of dust."

Fitz powered down Sleepy and placed the bot back in the case before inspecting his own results. "Yeah, not a lot over here either," he said, reaching for a pair of heavy protective gloves. "There's a bit of…a bit of an unknown isotope in there, but…that's-"

"Probably congruent with the metal from the Obelisk," Jemma supplied automatically before she grimaced. "Sorry," she apologized. "I didn't get that one wrong, did I?"

Fitz did his best to give her a small smile. "No, that…that was it," he assured her.

"Oh," she said in surprise, hesitantly stepping closer to him. "Good. So…are you just going to-"

"Yeah," Fitz nodded, setting aside the tablet. "I think it should be fine-"

"And…you've got the gloves, right?"

"Yes, I've got the gloves, Jemma," he said, weakly rolling his eyes. He held up his hands so she could see the protective equipment, and quickly glanced back at the Splinter Bomb to avoid having to see the worry on her face.

"Did you…did you want any help?"

"I've got it," Fitz muttered, grabbing a set of tongs and gingerly using them to grasp onto the object. He mostly used his good hand to control the movement, but he was thankful that Jemma was too busy clearing a space on the table to notice the shaking. He set the small disc on the surface, where it sat motionless for ten seconds as he and Jemma stared at it. Maybe it was their terrible history with all-things alien, but Fitz wasn't going to take any chances with this particular weapon.

It didn't look like it was going to start disintegrating anything in sight, though, so Fitz set aside the tongs and leaned in closer. Across the table, Jemma reached out a hand to point at something on the Bomb. "Are those markings-"

But she didn't get a chance to finish her question. Because this time Fitz was unable to stop himself from reaching out to push her hand away. "No," he admonished her, before quickly yanking his hand back. He stared at the stationary weapon, waiting for her to argue with him. He would have actually preferred that classic Jemma response to the one he ended up receiving.

"I'm…I'm sorry," she stammered. "I was…"

"I know," he sighed, resting his hands on the table. "Why don't I, um…why don't I do this and you look at those…er…look at the, um…surveillance tapes."

"Yes," Jemma agreed, her voice higher than usual. "That is…an excellent idea, Fitz." He wasn't sure what prompted him to do so, whether it was the words themselves or her tone, but when he glanced up at her it was like being transported back in time. Her cheeks were pink and she was avoiding his eyes and if it hadn't been for their current situation he could have sworn it was that first day working together. He'd pushed away her hand then, too, to make sure she didn't burn herself on the soldering iron. He hadn't understood the expression on her face then and he didn't understand the expression on her face now, almost like he'd hurt her or something.

As if she was actually offended that he was concerned for her safety. Which didn't make any bloody sense at all. Did she expect him to just let her touch a lethal weapon with her little bare hands and not do anything about it? If she did, then she obviously hadn't learned anything in the last decade.

He wanted to ask her about it. He wanted to ask her why she felt the need to treat him like he was a time bomb ready to explode. He wanted to ask her why she was even there if he made her so uncomfortable. He wanted to ask her why she didn't just leave him down in that med pod like he'd told her to. He wanted to ask her why she went to all that trouble just to leave anyways. He wanted to ask her so many things, but he knew he couldn't. He knew there was too much going on, he knew the timing was horrible, he knew that the last thing she needed was for him to give her any additional stress. She deserved better than that.

So they worked in uncomfortable silence. And as Fitz struggled to disassemble the weapon without causing massive destructive, and as Jemma sifted through footage on her computer, he was struck with the realization that as far as they'd come in the last eleven years, they'd managed to find themselves right back where they'd started. Fitz didn't have a lot of experience with déjà vu, but their current situation reminded him a lot of that first project they worked on together.

Ironically enough, so far this project was proving to be a lot less explosive.