A.N. Once again, thank you for your fantastic response and encouragement. You all are amazing and it thrills me to know that you are enjoying the story! As always, sorry for the delay, but here's a fairly long chapter to make it up to you! Though I do leave you on a cliffie, sort of... oops.

Also, the reason Sam is "pretty sure he has less than two-hundred-fifty-six minutes left to live" as stated in the little synopsis and referenced in the story, is purely for the purpose of playing off of the double meaning of the title, "To the Power of Two." There's the math side of it—so everything in the synopsis is raised to the power of two (2*2 = 4, 4*4 = 16, 16*16 = 256)—and then there's the people side of it—Sam and Libby, to the power of two.

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Libby moved so fast that one moment she was lying on the ground next to him, the next she cursed as she hovered over him. While staying low—conscious that their sphere of safety was small—she slipped her left arm under him and rolled him as far onto his back as she could, which meant he ended up partway on his side with his back pressed up against the concrete wall of the planter giving them shelter. His vision abandoned him for a moment as his damaged core adjusted to the shift, blinding him with an internal scream of protest. He managed to remain silent, however, which he counted as a win considering he felt like he'd just been stabbed.

When his vision returned, his field of view was filled with Libby, who kneeled over him, left hand pressed down on his own left hand, which he'd somehow managed to keep over his wound. Her face was a mask of anger, but Sam was pretty sure the anger wasn't directed at him.

"Dammit!" she swore vehemently. "Why the hell did you go and get yourself shot!?"

Scratch that, at least some of the anger is directed at me, he amended. He tried to reply, but just then she pushed down harder, stealing whatever breath he'd had.

"Don't answer that," she growled. "Save your breath."

I can't win, he mused ruefully, welcoming the brief distraction from their situation. From his situation.

"Keep that pressure on," she ordered, lifting her hand temporarily in order to grab the light cotton jacket she had tied around her waist. It was over ninety degrees outside and her family had teased her mercilessly for bringing it, but she'd stubbornly refused to leave it behind, stating that the department stores were sure to be cold and she didn't want to freeze. At the time, Sam had smiled at the family dynamics, choosing to refrain from entering the debate, but he'd secretly thought her crazy as well. Now, he was glad she'd stood her ground. She wadded the jacket up into a ball and carefully shifted his hand out of the way in order to place the jacket over the wound, before putting his hand back on top, pressing down once more.

It was only then that Sam finally noticed something he would have realized much earlier, had he not been fighting an internal war: Libby was right-handed, but currently, her right arm merely dangled uselessly at her side. Not only that, she'd chosen to remove her left hand from placing pressure on his wound in order to extricate her jacket, rather than simply grab the jacket with her right hand. Something was wrong.

He caught Libby's eye when she finally looked at him and then pointedly glanced at her useless arm, eyebrow raised in a facial expression he'd stolen from her.

"Hey, thief!" she protested half-heartedly, apparently reading his mind and clearly attempting to steer the conversation away from her arm. "You don't get to use my secret weapon against me," she admonished, nodding to his face.

He only raised the other eyebrow to join the first, demanding an answer.

She grit her teeth and sighed. "You're even more stubborn than I am," she grumbled, before grinding out, "I think it's broken."

Sam frowned. He couldn't see any blood on it, which meant she hadn't been hit by a bullet, so that couldn't be the cause… then he recalled the "snap!" he'd heard earlier, when all a hundred-sixty odd pounds of him had dropped on top of her. That would do it.

He closed his eyes in regret at the hurt he'd caused her and started to say, "I'm sor—," but got cut off.

"No! Don't you dare!" she hissed.

"I broke your arm!" he protested.

"No, you saved my life. Don't apologize for saving my life, Sam! You took a freaking bullet for me!"

He pried his eyes open to meet her gaze and shook his head.

She scowled. "What, you're gonna tell me that you didn't get shot because you pushed me out of the way? You just plain got shot?"

Well… he had nothing to say in response that wouldn't insult her intelligence, and he refused to do that.

"Uh-huh," she continued, unconvinced. "I'm not half as observant as you are—because let's face it, you're scary at how many details you catch—but I think it'd be pretty hard to miss the fact that this psycho took headshots! So either he just randomly decided to hit you center mass while literally everyone else got it to the head, or more likely, he was aiming for me. I'm not stupid, I know that," she nodded to the hole in his chest, "is exactly where my head is when I stand next to you."

Her face softened and she continued more gently, "You don't have to protect me from every little thing anymore, Sam. You're still my hero and always will be; nothing can change that. You're stupidly brave and selfless and have no regard for your own safety, which are character traits that I both love and hate about you; they make you the incredible human being you are—and I am fully aware that I would be dead twice over if you were any different—but they're also what puts you in harms-way."

He was speechless for a moment, trying to keep up with everything and wrap his mind around what she was saying. When it sank in, he felt warm to his core in a way that had nothing to do with his fiery, pulsing wound. Swallowing, he managed a smile. "Thanks I think? That was definitely one of the more backhanded compliments I've ever gotten."

She blushed. "Shut up. Suffice to say I'd take a broken arm over a hole in my head any day. So thank you for being you."

"Agree t-to disagree," he muttered stubbornly. I should have been more careful.

She rolled her eyes, all trace of softness gone and replaced by exasperation. "Oh, yes, I'm sure there was a way you could have both taken a bullet for me and landed under me so my arm didn't break. Yeah, it seems pretty obvious you messed up and purposefully did the bare minimum when it came to saving my life." She paused and stared down at him, waiting. When he said nothing, she continued, "Do you hear the sarcasm in my voice? Because I'm channeling my inner sarcasm pretty hard. Or is the blood loss impairing your perception?"

He huffed. "I caught it, thanks."

"Good, consider the matter closed."

Sam gave up and chose instead to focus his energy on more immediately important matters, like getting the stabbing pain to stop and being able to breathe. His body hadn't been in the best of shape to begin with that morning—when he'd awakened, his body had been stiff and sore with an impressive tapestry of bruises covering his torso, speaking to several bruised ribs and more—and now... In his current position, half sandwiched between the ground and the wall at his back, the pressure on his ribcage made him feel like it was collapsing in on itself, like a cave slowly collapsing under the weight of a mountain. He knew it was mostly in his head—his ribcage wasn't literally collapsing… yet—but that didn't make the reality any less worrying: he was finding it harder and harder to breathe. Not only did his broken ribs stab into his side with every breath, making his inhales sharp and ragged, but he felt like his lungs had less and less room to expand and would soon have no room at all.

"Libby, I need to sit up," he admitted slowly, aware he wouldn't be able to do it on his own.

"What?!" she exclaimed. "That's crazy! You need to stay there and keep the pressure on!"

He locked eyes with her and decided to be perfectly honest. "I am having trouble breathing right now," he wheezed out, "and it's only going to get worse the longer I go without medical treatment and the longer I lie here. So while I can, I need to sit up because—" before he was able to finish, he was interrupted by a cough that he couldn't suppress. His chest seized at the violent, unexpected movement, and for a moment, it stopped moving. He could not get his diaphragm to move to pull much needed oxygen into his lungs. The collapse that moments ago he'd felt was coming now suddenly seemed upon him and he was struggling, fighting, losing—

Then all of a sudden he was upright. The pressure did not disappear, but lessened significantly, and he drew in a gasping breath, all the while aware that Libby was whispering frantically, "Breathe, just breathe. Take a breath in and then let it out… please breathe, it's okay, you're going to be okay."

He listened to her voice, a gentle cadence and rhythm that sunk through the fog in his brain and gave him something to hold onto. Following her instructions, he took a slow breath in, then let it out. Then he took another. After several moments, his back now supported by the wall behind him, his breathing eased slightly. "Thanks," he murmured.

She nodded wordlessly and took a deep breath of her own, settling herself and letting the panic that had gripped her the moment Sam stopped breathing, dissipate.

They sat in silence for a moment, but once he was no longer under the immediate risk of passing out, Sam turned his attention to getting Libby the hell out of there.

"Libby, I need you to grab my phone out of my pocket," he ordered. "I'm sure they're already on their way, but we need to see if we can get in touch with SRU…."

The last people he wanted to call were his team—he was positive all of them were still livid—but he would do anything to help Libby, even ignore his hurt and fear of being further ostracized by them. Then it occurred to him that he wouldn't even need to talk to his team, as they weren't on rotation. Small mercies, he thought to himself, though he almost wished they were on call. They were the best, and no matter how angry they were with him, he knew they would put that aside to get the job done.

Libby hesitated, before pursing her lips and returning his order with one of her own. "Okay, I'm removing my hand which means you need to keep that pressure on yourself."

He nodded dutifully and she lifted her hand, moved it to his pocket and pulled out his phone. Her face told him what was wrong even before she turned it around to show him the shattered, lifeless screen.

"Dammit!" He slammed his head back against the wall in frustration as yet another thing didn't go their way.

"Hey! It's not that big of a deal!" Libby argued, dropping his useless phone to the ground and placing her hand on his chest again, trying to calm him down. "Like you said, I'm sure tons of other people have already called them! And look!" she jerked her chin towards the edge of the square. "The cops are already here."

He followed her gaze and saw authorities setting up a perimeter, staying as far away from the plaza as possible. Yes, they're here, but they have no idea where the shooter is and probably none of the witnesses will be any help narrowing it down. Witnesses were notoriously inaccurate and contradictive, but it was pointless to argue with Libby since they had no phone and no way to access one. Sam couldn't help a small grimace of a smile as a thought occurred to him. At least Ed can't yell at me for not having my phone on me this time. Then his thoughts turned darker and he scowled. But given his attitude towards me right now, he'll probably yell at me for breaking it, even if it happened when I saved Libby's life.

They lapsed into silence. With nothing to distract him, Sam found himself rapidly losing the battle of wills he was waging; the inexorable blood loss slowly gaining the upper hand. He couldn't help but notice that Libby's jacket was already almost soaked through, that his hand was bloody enough that droplets dripped from his fingertips onto his already saturated shirt, that every breath he took made him feel worse and that soon he'd probably be drowning in his own blood. Literally. The external bleeding was slowing due to the pressure Libby was exerting—so long as he didn't move and break up the miniscule amount of clotting that had occurred—but there wasn't a damn thing they could do about internal bleeding. Not here, anyway. And Sam was sure he was bleeding internally. The longer he lay there, the more useless he became and the less chance he had of keeping his promise to Libby.

Don't go down that road, Sam, he chastised himself. That's not going to lead you anywhere positive or productive.

He needed something to take his mind off of his own predicament, something to ground him. So he searched the plaza desperately for something, anything, and his eyes settled on the father and child hunkered down not too far away from them. The child stared back at him, face streaked with tears, eyes wide and scared. The father held her close, his arms encircling her small frame as if his love would be enough to protect her from all the atrocities around them. From everything that was to come.

As he stared at the pair clinging to each other, he distantly heard a voice projected into the square by a megaphone, instructing occupants to call a number set up for them. If only we had a phone…

The sun beating down on them made him sweat, but the hot pavement beneath them seemed to suck his energy away with each passing minute, pulsing in time with the throbbing aches that wracked his body. The blare of the megaphone became a background buzz, a comforting distraction as the heat lulled him and made his eyes feel heavy, and he wondered briefly if he closed his eyes, what would happen?

"SAM!"

A voice shouted in his ear, jolting him back to reality as he snapped his eyes open. It disturbed him that he hadn't ever felt them close, had only thought about it.

"Don't do that. Don't zone out on me!" Libby yelled, shaking him gently.

He drew in a breath to center himself and muttered an apology, reaching his right hand up to clasp her uninjured forearm, a gesture less to comfort than to express that he was still there.

"It's okay," she whispered, blinking her eyes rapidly. "Just don't do it again. Promise?"

He couldn't make that promise and instead remained silent, turning his attention back to the situation at hand. Things need to change, fast, and not just for my sake. As hot as it was, no one was going to be in good condition if this went on for too much longer, and the younger people such as the child and Libby would be hit hardest. And, for all he knew Libby could go into shock due to her injured arm, especially if she damaged it further while moving it around in order to take care of him.

"We need a phone," he murmured, unable to stop himself from shifting slightly in agitation at his inability to do anything.

"Sam just let it go! You're working yourself up over something we can't change! Other people have called them! The cops are already here! Let someone else be the hero this time!"

"Sure other people have called, but I doubt any of those other people have a clue as to where the sniper is!" he snapped, temper fraying. He regretted it immediately; Libby didn't need his harsh words. It wasn't her fault, she was just trying to look out for him. He looked up at her, prepared to apologize, but stopped when he saw her face.

Libby didn't look hurt by his outburst, instead she looked almost… hopeful. "Are you saying you know where he is, more so than just somewhere on the opposite side of this wall?"

Sam bit his lip as a rib shifted ever so slightly inside him, before drawing in a shaky breath. "Yes, I have a pretty good idea of where he is. Either the tan building or the steel-gray one with the arched front. Twentieth floor or up. Don't!" he hissed sharply as Libby instinctively turned to look at the buildings in question.

She whipped back around with a sheepish look on her face, which quickly morphed to amazement. "How the hell do you know that?"

He hesitated before stating bluntly, "I watched how people fell and felt how I was hit. That gave me a pretty good idea, but it's only an estimate and to be honest, something seems a little off about how it all went down… but I can't quite put my finger on what. Either way, the SRU should know."

"But you think you know where the shooter is."

"Yeah."

"Which means if you're right, the SRU won't have to spend as much time narrowing it down themselves and searching every building, which means we won't be here as long, which means you'll get to a hospital sooner… Which means we need a phone." Her resolve shone in her eyes, before she dropped his gaze and turned to stare out into the square.

She met eyes with the father and daughter and mimed making a call, asking if he had one. The man wearily shook his head. She cursed under her breath before continuing to scan the plaza, then all of a sudden she froze.

He followed her gaze to where her bag sat on the ground from when she'd dropped it in the chaos, about ten feet from their current position.

It wasn't hard to connect the dots. "No!" he exclaimed vehemently.

"Sam, we need a phone and that's the closest one."

"It might be broken!"

"True, but it's our only chance."

"Then I'll get it!"

"Don't be stupid. You've been shot. You move and all of the clotting that's happened goes to waste and you bleed out sooner." She gazed earnestly at him. "You've already saved my life today, it's my turn to try to do the same for you."

And before he could do anything to stop her, she darted out into the plaza, out of their sphere of safety. It was only ten feet, but ten feet might as well have been a mile. If the sniper was looking this direction… Sam needed a distraction. He needed to throw something, make some other sort of movement that would draw the sniper's eye.

Gritting his teeth, he bent his knee, jerked his foot towards him and seized the one shoe still left on his foot—absentmindedly, he realized the other must have come off in the scramble. Shoe in hand, he looked up and watched as Libby reached her bag, snatched it up, and turned around, eyes finding his as she sprinted back to him. But no matter how fast she moved, she still had ten feet to cover. Ten feet. A mere few seconds, but those seconds had her in the middle of the square, completely exposed to the shot of a gun.

Desperately, he hurled the shoe high in the air and towards her, and had to laugh in dismay at his effort; what was a shoe compared to a five-foot tall person running like mad? Nothing. It probably wouldn't do anything, but he hoped… he hoped it might flash across the sniper's scope or out of the corner of his eye and makes him hesitate just a breath, because a breath was all Libby needed to make it the last few steps back to him…

A deafening "BANG!" ricocheted throughout the square.

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A.N.2. Sorry, not sorry. Hope you enjoyed!

Also, Libby's jacket is not just for convenience's sake, it's actually how I feel in the summer and what I do.