Jack Dalton studied his partner from across the small clearing, his eyes narrowed in suspicion as Mac slowly opened and closed his hands. Mac’s pupils were blown wider than the midday sun trickling down through the gaps in the leaves would warrant, and he watched his fingers curl and uncurl with an expression of uncomfortable fascination.

Jack’s feet hurt from running across the uneven, rocky terrain, but he heaved himself to his feet anyway and casually made his way over to his distracted partner. Mac actually jumped when Jack’s hand came down on his shoulder. His blue eyes did a poor job of hiding the anxiety behind them, which just made the alarm bells clang louder.

Lowering himself onto the dirt beside his friend, Jack asked with a calm he didn’t feel, “Mac? How’s it goin’, bud?”

Mac cleared his throat and stowed his hands in his lap, though Jack didn’t miss the way his eyes kept twitching down, or the way his fists continued to clench and unclench even as Mac strove to turn his attention to Jack. “Good. Hopefully once Riley gets us back online, we’ll be well on our way to exfil.”

“Uh-huh.”

Mac opened his mouth as if to say something, then shook his head and looked down again.

Real fear blossomed in Jack’s chest at Mac’s uncharacteristic behavior, and he decided that the subtle, friendly approach was out. “Okay, out with it, Mac,” he ordered abruptly, his Texas twang even more pronounced since he’d spent the last four days in the heart of the Southern US on a mission to take down an up and coming domestic terrorist group that had made their base in the heart of the Appalachians.

This mission involved some truly nasty stuff – including bioweapons and chemical warfare. This band of rogue scientists-turned-domestic terrorists – they called themselves Curis, which was, according to Mac, a rough Latin translation of healthcare – had been growing steadily in numbers and power over the past few months.

Matty’s intel, Riley's hacking skills, and some good old fashioned teamwork had eventually led them to the terrorist organization’s home base – an abandoned mental hospital in the heart of the Appalachian Mountains, where poverty and corruption often turned a blind eye to crime. The Appalachians were the oldest in the U.S. and though they weren’t the most imposing any longer, they were rugged and pocked with sheer drops and steep inclines and populated with black bears, cougars, and a handful of venomous snakes. And enough superstition still lingered in those mountains that tales of Bigfoot and other urban legends and eldritch horrors kept most of the population well away from remote, unmapped insane asylums entombed within the craggy rocks, gaping caves, and thickly growing trees of the ancient mountain range.

Their mission was simple: Get into their base and steal the plans for their newest bioweapon, as well as any information they could snag on the organization itself. These mad scientists were a truly paranoid bunch and didn’t keep digital records of their research, clients, or future plans, so there had been no way to hack the information. Riley had still made herself invaluable from the Phoenix when it came to navigating the winding corridors of the mental facility, though.

Jack had wanted to go ahead and take the whole operation down while they were there, but Matty had ordered that under no uncertain terms were they to take this organization on by themselves. This mission was mostly reconnaissance, as most of the intel Matty had been able to procure had been … extracted from a tight-lipped lower-level member they’d lucked upon last week. Until they knew the scope of this organization and exactly how they operated, this was a grab-n-go mission only (Jack’s words, not Matty’s).

And so they’d grabbed. They’d tried to go, but one of the guards hadn’t had his radio on, and since the radio waves were how Riles had been keeping track of and helping them avoid their enemies, Mac and Jack had been caught by surprise. Still, after a few exchanged punches and some hardcore sprinting, the pair had made it back to a nearby clearing without serious injury. Jack had some bruised ribs and Mac had been knocked into an industrial shelving unit filled with beakers and jars and vials and had a sore back and a shallow cut on his arm to show for it, but otherwise, they’d made it out with their prize only a tiny bit worse for the wear.

Or so Jack had thought.

He knew Mac well enough to realize that his partner was hiding something from them, something that had him worried. Mac worried was scary enough – this was the man with the plan, the dude who exuded a natural confidence 24/7 because he was smart and resourceful enough to get himself out of pretty much any predicament. The few times Jack had seen Mac truly worried he could count on one hand, and each time had involved the direst of circumstances. And if Mac felt the need to hide whatever was scaring him, that just meant things were even worse than Jack had realized.

“C’mon, hoss,” Jack urged when Mac didn’t immediately respond. “How bad is it? What are you hiding?”

Mac’s face flushed red, and he crossed his arms over his chest. Finally, his fingers were still, but it was an unnatural stillness – Mac was always moving, always fidgeting, always working on something. To see Mac’s hands hanging almost limp from his wrists carved a great pit in his stomach, a pit that was promptly overflowed with panic as Mac finally, eyes bright with fear, answered honestly.

“I think… I think it’s bad.” His voice was barely even a whisper. “Really bad.” He turned his neck and Jack’s blood froze. There, sticking out of Mac’s neck, was a small dart, probably from a blow gun.

Jack swallowed hard, almost choking on the lump in his throat as he plucked the dart from Mac's neck and carefully pocketed it. “Okay,” he said softly, determined to keep his voice low, even, and calm. If Mac were already on the verge of panic, then Jack’s own fear would only send him spiraling. For Mac’s sake, he had to keep a level head, figure out how to fix whatever the hell was wrong with Mac, and get to exfil before night fell. “Okay,” he said again, then took a deep breath and let it out through his teeth. “What’s going on, Mac? What’s wrong with your hands?”

“It must have happened sometime during the fight or as we were running away. I didn’t even realize I’d been hit until we made it to safety, and by that time, my hands…” He trailed off. “Jack… That bioweapon they were working on, I don’t think it was only in the planning stages like we thought.”

Jack felt bile rising in his throat. All he knew about the poison was that it was an experimental paralytic. Even though he now knew with certainty the answer to his question, he couldn’t stop from asking it again, perhaps in the vain hope that it wasn’t what he thought. “Mac. What is wrong with your hands?”

Mac’s voice broke and his face was tight with fear as he answered: “I can’t feel them, Jack.” A deep, shuddering breath. “I can’t move them at all.”

***

Less than half an hour later, Mac stumbled after Jack, his arms hanging limply at his sides. He’d lost full control over them far quicker than he’d anticipated. When he’d realized that he’d been exposed to the not-quite-as-hypothetical-as-they’d-hoped paralytic agent, he’d expected it to act similarly to the poison this new toxin was being developed from, which offered a slow and horrific death via paralysis.

“So tell me,” Jack called back as he struggled through the choking sea of undergrowth, brambles, and what looked like a healthy amount of poison ivy (Mac was very thankful for their thick, protective boots). “What exactly is runnin’ through your veins right now?”

The Tennessee air was thick, muggy, and humid, and Mac felt like he was swimming rather than walking through it. Sweat poured down his face in thin rivulets that felt almost like tears. They tickled, or maybe that was just the mosquitos. Mac wanted more than anything to scrub his hand across his face, but no matter how urgently he willed his arm to move, nothing happened. His stomach twisted in a stark terror he had never felt before, and the icy claws of panic tore at his chest like a caged monster trying to escape.

He knew that Jack was just trying to make sure he knew what they were dealing with. He also knew that the Phoenix had already called in one of the leading toxicologists in the country, and that this specialist and his friends were listening in over the comms, silently analyzing everything he said, doing everything possible to prepare for Mac’s return. The more information they had, the better chance they would have of reversing the effects. Of saving his life.

Mac swallowed heavily, forcing any lingering anxiety out of his voice. He knew Jack was barely hanging on at this point, and if he showed weakness, revealed to his partner how scared he really was, then that would heighten Jack’s own worry. The guy was already under enough stress as it was. He adopted what Jack affectionately (or irritably, depending on the circumstance) coined his “Einstein voice.” This was a tone and cadence he’d learned growing up with an emotionally distant and highly logical father. He liked Riley’s term for it, Macsplaining, only slightly better.

“I didn’t get a chance to read through all the research notes,” he panted, and his heartbeat thundered in his ears. “But from what I did see, this experimental toxin is based upon curare poison.”

“Who-rah-ray?” Mac’s lips curved into a slight smile as Bozer’s voice crackled over the comms. Of course Boze was still there, listening, waiting, there. He had always been there for Mac.

“Curare,” Mac repeated. “It’s derived from resources natural to the Amazon. A powerful paralytic. It’s how many native tribes hunt for game – and a variation of the formula is used in war as well.”

“So, these scientists just took this curare poison and, what, modified it?”

“I’m not entirely sure, Riles,” Mac huffed. His foot caught on a tree root and he pitched forward into Jack’s back, his arms swinging uselessly at his sides.

“Whoa, partner,” Jack said gently, and his dark eyes were glittering when he turned to steady his friend. “Maybe we should take a quick breather.”

Mac shook his head almost frantically. Though this variation was taking longer to incapacitate than curare itself, he could already feel the tingling in his feet. He needed to press forward for as long as he could. If he was right about the poison’s properties, he’d be unable to walk on his own soon. Unable to move at all a bit after that. When his vocal cords seized up, he’d be unable to talk.

Instead, he insisted, “No, I’m fine. Let’s keep going.” He plowed ahead, pushing past Jack in his haste to do something other than sit around and wait for his body to betray him. Addressing his friends back at the Phoenix, he explained, “All I know is that they used curare as the baseline for their experiments. I’m guessing they wanted to refine it, make it more potent, or at least easier to mass produce and distribute over large populations in a less concentrated form.”

“So what happens now?” Bozer’s voice was subdued, anxious, though Mac could tell he was trying not to show it. “I mean, if the poison keeps doing its thing?”

If this new toxin behaved similarly to curare, his lungs would freeze and he would suffocate, betrayed by his own body. A shudder passed through him. No need to bring that up to his friends yet. Maybe this poison had been adapted to incapacitate without causing death. Considering the people who had developed it, that scenario was very unlikely, but Mac found himself unable to voice the grimmest of possibilities aloud. Mac forced his teeth to unclench, the roaring panic having locked his jaw in place and hedged, “Based upon how quickly the paralytic is taking effect, I could be completely paralyzed in a couple of hours.” Given Jack’s face at this sugar-coated answer, Mac was glad he’d left the worst part out for now.

With any luck, they’d make it to exfil and be on their way to a hospital before Mac’s body began its final betrayal.

***

They were forced to take a break fifteen minutes later when Mac’s legs finally stopped working. Jack caught him right before he could crash onto the mossy ground and carefully propped him against the smooth trunk of a great birch tree. Mac allowed his head to flop back against the papery bark in exhaustion as Jack carefully arranged his legs in front of him. The numbness in his body had taken residence in his soul, and Mac watched the proceedings with a detached interest.

At least he wasn’t in pain, he thought. In fact, he felt nothing at all as Jack gently jostled the limbs. His partner could have slammed his feet into the ground and Mac wouldn’t have noticed unless he had watched Jack do it. Of course, with the lack of pain came the lack of control over his extremities and the increasingly real knowledge that this paralytic was working far too quickly for his liking and that he would soon be struggling to breathe, and that his death would not be anywhere as painless as his arms and legs were now.

Jack finished with Mac’s legs and stooped over his bag, pulling out a canteen of water. “Hey, Mac,” he said quietly, like he was addressing a spooked horse. “How about we get some water in ya?”

Mac shook his head and panic lanced through the blissful nothing he’d been feeling as the familiar tingle that foretold paralysis flared through his neck muscles at the movement. He hadn’t even realized his stomach had turned into the North Sea, with great waves of sickness swirling around, until he said it. Logically, he knew he needed to stay hydrated, especially since his ability to swallow could soon be taken away from him, but the thought of drinking or eating anything summoned bile to his throat.

Before Jack could argue, Matty’s voice sizzled over the comms. She, Bozer, or Riley had been busy planning Mac’s extraction and treatment with Dr. Bonner, the toxicologist, but someone had been checking in about every ten minutes. “How’s our boy doing, Jack?”

Mac watched languidly as Jack valiantly strove to keep his face arranged into a facade of calm and failed to keep his voice steady, “He’s, uh, hangin’ in there, boss.”

Matty’s voice was firm but kind as she scolded, “I appreciate your attempt at levity, Jack, but Dr. Bonner needs a real answer. Mac?”

Mac cleared his throat and somehow managed to find his voice. “I… uh, the toxin is progressing slower than curare, but I’m beginning to suspect that’s what Curis was working toward. It’s very possible they are trying to drag out the paralysis to build fear. Maybe as a torture technique.” Certainly effective in that regard, he thought darkly.

“That’s all well and good, Mac, but she didn’t ask about the poison,” Jack reminded Mac gently, squatting down in front of his younger friend so that they were eye level. “How are you?”

“I have lost complete control over the skeletal muscles in my arms and legs,” Mac answered brusquely. “My neck is starting to weaken as well.”

“What about your chest?” With all of her hardness and training, Matty couldn’t quite keep the anxiety out of her voice. Of course Matty knew about the final stages of the poison. The toxicologist would have informed her of what to expect.

Jack, however, had heard no such thing. “Chest? Matty, what are you talking about? Mac didn’t mention anything about chest paralysis.” Jack’s voice was now tinged with panic he could no longer hide.

Mac sighed. “I didn’t want to worry you–” At Jack’s incredulous look, he added, “–more than you already were, but… If this poison behaves like curare, then the final stage is paralysis of the lungs.”

“And what does that mean, exactly?” Mac knew that Jack understood exactly what it meant, but he was clinging desperately onto any hope that he might be wrong, much like Mac himself had done earlier.

Matty, never one to hold her punches, answered, her tone clipped and scared: “It means that you need to get back on the move, Dalton. If Mac’s lungs seize up before you he can get medical help, then he will suffocate.”

“Shit,” Jack swore loudly, his dark eyes glittering as he regarded Mac, limp against the tree.

“Shit,” Matty agreed, and Mac couldn’t help but chuckle at her assessment. She pressed on: “Okay, so as you know, we’ve rerouted exfil to the smallest nearby clearing that can fit the chopper. It’s going to be a squeeze and we wouldn’t normally risk it, but we need Blondie in a hospital, stat. Still, you’ve still got about five miles to go, and it’s not exactly the easiest terrain, so let’s hustle.” Jack nodded even though he knew Matty couldn’t see him, and he grunted as he rose to his full height. He still held the canteen loosely in one hand and was about to pack it again when Matty added, “Oh, and Jack – the doctor says to get as much water into his system as you can – and Blondie, don’t you dare fight him on this. It’s only a matter of time before your throat muscles stop working, and we’re not fighting this hard to save you from this toxin just to lose you to dehydration.”

Although the mere thought of the water made Mac’s stomach clench, he tried to nod, found he couldn’t, and swallowed heavily, grateful that he could still do that, at least. “Yes, ma’am.”

Jack’s hand carefully cupped the back of his head and tilted it back, though Mac felt neither his touch nor the motion. He managed to get a few good gulps of water in him before he felt his throat muscles weaken, a strangled gurgling sound the only indication that he was choking. Jack pulled the canteen away and leaned back, guilt festering in his eyes, but he didn’t apologize. Mac knew it was because he couldn’t find the words to say, and honestly, Mac was glad.

It’s not like he would be able to respond now, anyway.

Jack lifted Mac from the ground and held him like a bride – a floppy, ragdoll of a bride – as they made their careful way toward exfil and prayed they wouldn’t be too late.

***

It was nearing dusk when they made it to the clearing, the helicopter pressed in on all sides by trees. The mosquitos had called their friends with the promise of a great meal, and Jack and Mac were covered in itchy bites that only Jack could feel.

Mac was completely limp in his arms, his body dead weight, head lolling back against the crook of Jack’s arm, face lax and pale. He hadn’t spoken for a couple of hours at least, unable to form words or use his vocal cords, but his eyes remained open. His chest still rose and fell somehow, and despite the cocktail of fear and acceptance swirling in Mac’s glassy eyes, his breathing was slow and steady, almost calm. Jack suspected that Curis had somehow managed to manipulate the poison to attack certain parts of the body first for optimal torture. He didn’t have any clue how anyone could do that, or if it were even possible, but the systematic way that Mac’s motor functions had deteriorated, leaving at last only his lungs and eyes with full range of motion, was too cruel to not be deliberate torture, he was sure of it.

It had been hours since Mac lost the ability to move the muscles in his face, but the toxin hadn’t seemed to progress any further and Jack was beginning to hope that maybe this modified version of the curare poison was only meant to incapacitate and not actually kill. It was as he laid Mac down on the waiting stretcher that he saw the slightest of shifts in Mac’s eyes, the anxiety turning to panic, and his eyes traveled down to see that Mac’s chest was jerking, spasming, as his kid desperately fought the paralysis that was now creeping into his lungs.

Jack forced himself to step back as the field medics that accompanied every exfil – sorely undertrained for something like this but welcome all the same – swarmed the stretcher. Jack’s mind was spinning, his whole body screamed at him to do something, to help, to save Mac, but there was nothing he could do, Mac was suffocating, God, please, no, he was dying, and there was nothing Jack could do.

Jack’s eyes found Mac’s face once more and his heart skipped a beat as he saw his kid was still alert, still fighting. His filmy blue eyes were fixed stolidly on Jack, and a single tear rolled down his cheek.

“I’m here, kid,” Jack called out, his voice lost in the urgent voices of the men and women trying to save Mac’s life. “I’m here.”