Author's Introduction: A series of moments exploring how Booth went from disliking Brennan to being her 'knight in standard-issue FBI armor' in the first year of their partnership, followed by his changing feelings about her as they continue to work together. I am marking this as incomplete because this is the first of a series of stand-alone chapters. Each chapter is complete in itself, but they all will build on each other. At the moment I have seven chapters complete; I'm working on a few more that I definitely plan to publish.

A Note About the Title: A Catalyst in chemistry is a substance that accelerates a chemical reaction, without increasing the temperature and without being changed itself. In human terms, a person can be a catalyst if they cause a change or action between two people without being affected or changed themselves.

Disclaimer: I do not own or benefit from Bones in any way. I will be borrowing dialogue and incidents from select episodes and building upon them to draw out certain themes. In this first chapter, credit for episode dialogue goes to Hart Hanson.

Catalyst in the Partnership

1.

Angela – On the Hue of Generosity

"You must know about her family. Both parents disappear when she was 15. Probably counts as the 'real world.'"

Special Agent Seeley Booth couldn't believe his ears, or his eyes. The cadre of scientists, complete with one unconventional forensic artist, stood around a giant holographic projector straight out of Star Trek and showed him a nifty movie that was based on circumstances and conjecture. Young political intern Cleo Eller was stabbed, her fingertips removed, her skull smashed, and evidence planted to misdirect the search for a suspect. And there stood the arrogant Dr. Temperance Brennan, Forensic Anthropologist Extraordinaire, agreeing when one of her minions claimed the first place Booth ought to look was a senator's basement.

Astonished, he asked, "You expect me to declare war on a United States Senator based on your little holographic crystal ball?"

Brennan's arms were crossed, her eyes narrowing in irritation. They'd been through this argument before, and it hadn't ended well that time, either. He'd dragged her out of a room and she'd struck him with a vicious blow to the zygomatic. She felt the same tide of fury rising now, the same disbelief that Booth was once again dismissing the evidence just because he didn't understand how to interpret it. "It's not magic. It's a logical recreation of events based on evidence."

"No more valid than my gut," he countered meaningfully. No way in hell was he going up against Senator Bethlehem with her squint squad's version of an Agatha Christie dénouement. Glaring at each of them in turn, he cut his gaze back to Brennan and found himself admiring the sparks flying out of her hammered-steel eyes. It had been a year, and he'd forgotten how stormy she could get. Booth decided he quite liked getting her all riled up regardless of the danger she posed to his person. Even though his cheek and his ego had both ached for days after the last time they'd dueled, she'd been so intensely provocative that he'd been unable to forget her. Booth had gone to great lengths just to be in the same room with Brennan again but he wasn't about to give her the satisfaction of backing down.

He's pissing her off on purpose, Dr. Jack Hodgins realized. The resident expert on soils, insects and plants watched the interplay between his boss and the FBI agent with interest. He'd known that Booth had somehow gotten off to a bad start with Brennan a year ago. She'd stormed into the lab like a hurricane, raging that he was arrogant, stupid, a bully and she most assuredly wasn't ever going to speak to Special Agent Seeley Booth of the FBI ever again. Never. Ever. The tempest had raged throughout the lab for two hours that day, ceasing only when Angela dragged Brennan out "to blow off some steam."

In all the time Hodgins had known the unflappable Dr. Brennan, that was the first time he'd seen her careening out of control. And it was the last, until right now where she seemed to be on the verge once again. For a man with anger management issues of his own, seeing the hyper-rational scientist explode into fury was exhilarating and just a tiny bit terrifying. She'd kept her temper so tightly leashed that no one even knew it was there, thus the heights her rage could reach once it escaped had shocked everyone the first time around. Hodgins glanced at Angela and saw her eyes widening in apprehension of a second performance as well.

Brennan's eyes were narrowed, her body stiff, the fury rolling off of her in waves like a gathering storm surge. Hurricane Temperance was about to make landfall and Seeley Booth was clearly goading her on purpose, blowing heat into the system and watching the thunderclouds churn. Hodgins shook his head as the FBI agent's legendary arrogance clashed with Brennan's equally impressive temper. The man might have a gun, but Hodgins was fairly certain Brennan would win if it came to physical blows, and boy did she look ready to blow.

When she was angry, Temperance was anything but temperate. She was beautiful and dangerous in the way of Siberian tigers, blue eyes flashing and coiled muscles rippling with restrained strength. Where tigers had sharp claws, Brennan had a razor sharp tongue—she could flay a man alive using words alone, then follow it up with a beating calculated to bring about maximum pain in minimal time. Clearly she was dangerous: last year she'd beaten up a judge and cold-cocked an FBI agent all in the same 24 hours. Only two days ago, Angela had watched in glee while Brennan dropped a Homeland Security agent over 6'6 and 300 pounds as if he were a ten year old. Apparently Booth was unafraid of her, but he was the only one not quavering.

The intern, Zack Addy, interrupted nervously when he saw the sparks shooting out of his mentor's eyes and the blatant disregard emanating from the FBI agent. Reading social situations wasn't his strong suit, but even he could see the confrontation brewing. Remembering the last time Booth had rigged Dr. Brennan for an explosion, he thought it might be prudent to cut the fuse. Perhaps a bit of logic might help. "A good hypothesis withstands testing. That's what makes it a good hypothesis."

Then Zack paused to wonder if Agent Booth even knew what a scientific hypothesis was. Pose a question, then design an experiment to prove or disprove the question. All he had to do was find the cement floor to prove the hypothesis about the senator right or wrong. It was simple—why couldn't Booth see that?

"This is not a hypothesis," Booth sneered. "You have a dead girl and a United States senator." It was a simple, common-sense rule—why couldn't these clueless squints see that? One did not go up against powerful people without all their ducks lined up. He'd been over this before with Brennan, didn't she remember Judge Hasting? Evidently she still didn't know how it worked, the way of politics and power. It seemed working in this lab had sucked all common sense out of their heads.

Booth pinned his gaze coldly on Brennan, letting her know she was out of her element. "This is exactly why squints belong in the lab. You guys don't know anything about the real world."

If he hadn't been looking at her, Booth would have missed the arrow of pain that darted across her features before her entire body stiffened and she brought herself under control. It was only a moment, but a telling one. Just that fast, the fire in her drowned under a surge of ice water. Brennan's face hardened, the sparks in her eyes subsiding into the lifeless grey of a frozen lake. She flicked her gaze over the assembled scientists, taking them all in with a frosty sweep. "Come on. We're done here."

She turned and walked out, head erect, shoulders slung back proudly. At least she didn't hit him this time. Booth counted that as progress.

Wordlessly, the others filed out behind her, each one casting a hard, angry glance Booth's way. Their disapproval washed off each one of them in waves as they departed, leaving Booth to wonder why they were so sensitive.

"Wow." Irritated, he tossed a red poker die in his right hand, a relic from his gambling days and reminder of how recently he'd overcome that vice. Catching it, he turned his head and saw one squint still standing there. His glance oozed disdain. "Touchy," he groused.

Only Angela Montenegro remained, because it was her office. But the lovely Asian woman paused in her studied disregard of the not-so-special agent to offer an explanation for his unanimous dismissal. "You must know about her family. Both parents disappeared when she was 15. Probably counts as the 'real world.'"

Booth scoffed. "Yeah, I know the story. I read the file. The cops never found out anything."

Angela agreed quietly. "Yeah. Brennan figures, maybe, if someone like her had been there…."

"For someone who hates psychology, she sure has a lot of it." He shrugged dismissively, hands jammed into his pockets.

Angela stared at him. Glared at him. Waited for him to get a clue. Nothing.

She took a step closer, suddenly understanding what had pissed Brennan off so much a year ago. Her eyes flashed dangerously. In her own way, Angela was just as hazardous as Brennan. "You may be cute, but you are also a complete ass."

"What?" He stepped back, surprised at the rapid change of mood.

"Think about it, G-man. A kid with no extended family suddenly has no parents. What the hell do you think happened to her after that? Huh? Where do you suppose she ended up?"

"Not with relatives…." He guessed, since Angela had just indicated Brennan didn't have family.

"Foster care."

He winced.

"Do you know how rare it is for a foster kid to even make it into college? Let alone earning multiple PhDs. Do you have any idea how hard she's worked, how much she's had to overcome?"

Feeling chastised, Booth looked away. Shrugged. He wasn't sure he wanted to think about it, or to allow sympathy or admiration to soften the righteous irritation he'd been harboring for months. Brennan was the one who had gone nuts, why should he have to consider the possible causes underlying her evident insanity?

"Do you have any idea how many times Brennan has been kicked by life in general, but she gets up and keeps working?"

"So, what are you saying. You're her biggest fan?"

"We all are." Angela took another step into his space, radiating hostility and a protective instinct that was quite at odds with her usual 'flighty artist' demeanor.

"You want to keep working with Brennan? You need to look deeper. There's more to her than you think. I promise you, if you really pay attention and get to know her even a little, you will see what we see. You'll understand why they all follow her and why I'm just barely holding back from kicking your ass."

Booth barked a laugh. "You?"

"Me. Hodgins. Zack. Even Goodman. Don't you dare slight her, or we will all be lining up for a swing. You understand me?"

"Are you threatening me?" he asked incredulously.

"I don't make threats," she assured him. "I make promises."

A chill rolled across Booth's shoulders. Angela was serious, seriously threatening him. And all the other squints did seem poised to strike out on Brennan's behalf as well. Given how arrogant and irritating the forensic anthropologist was, he couldn't credit such loyalty. They should hate her, be willing to sabotage her; instead they were lining up in her defense. Something didn't add up.

His confusion must have been obvious because Angela's eyes suddenly turned a warmer shade. "Tell you what, I'll give you your first clue for free."

She walked over to her desk, picking up a skull that was crazed with fracture lines all over it, like a crackly old porcelain cup. "This is Cleo's skull. You remember how many pieces there were?"

He nodded, remembering slivers and shards by the hundreds that Brennan had cataloged at the pond, taking care to wrap each as if it were porcelain rather than bone. Disbelief etched his features as he regarded the reconstructed whole. Every piece had been carefully glued back into place, leaving the skull nearly complete again, aside from a triangle patch of clay centered in the forehead and a second clay patch bridging the arch of one cheek. Tiny pencil erasers had been glued over the facial bones, marking the estimated tissue depths that had guided Angela's reconstruction of the face.

Angela traced over the skull almost lovingly. "After traveling for 26 hours, winning a fight against a much larger Homeland Security agent, being arrested at the airport, dragged out to a crime scene and working all night to retrieve a skeleton from a pond, Brennan was still at work the next day. She prepared said skeleton for cleaning and examination, then proceeded to stay awake all night for a second night to glue over 1000 bits of bone back together into this skull. Two nights, no sleep."

She pinned him with a hard glare. "That's the kind of dedication Brennan gives to her work, to the nameless people who come into this lab. She gives up everything for them, including food, sleep and any inkling of a social life. I know it looks to you like she doesn't care; that just shows how little you know. Detachment is the only way she can survive all the death and destruction she sees. It gets to her. So, when people call her cold … it hurts her."

Setting down the skull, Angela gave her second warning shot. She looked directly into his eyes, her words making clear she knew he'd called Brennan cold during their previous case. "It hurts her a lot, Booth."

A flush of shame and guilt brushed his cheeks darker for a moment. "I had no idea she missed two nights of sleep."

"She's not going to tell you. She's never going to tell you any of this—that's not who she is. So it falls to us, the people who've bothered to know her. I'm telling you what you need to know. Listen carefully. Brennan is honest. Dedicated. Modest—no, don't you dare interrupt."

He'd drawn in a breath, about to sputter that Brennan threw around her PhDs like a fist, smashing him in the face with them repeatedly. And all those comments she made about her intelligence and his lack thereof. "I'm the best in the world," she'd said. That was modesty?!

But Angela steamrolled right over him, apparently reading his mind in the process. "Yes, she is modest. When she tells you she has three PhDs or an IQ of 183, she's just stating a fact. But the other stuff, the amazing stuff, that's what she won't talk about. Things like skipping food and sleep to reconstruct a stranger's skull. You have no idea of her generosity, the things she's done for others. She just does them, never tells anyone. Did you know she started a scholarship in the name of Jemma Arrington? The singer in your first case together."

His expression must have indicated this was the first he'd heard of this. Angela nodded and continued. "She didn't tell me either, I read about it in the Post. That's the kind of modesty I'm talking about."

"Brennan started a scholarship?"

"She used the profits from her book: the whole check, including any future royalties. She didn't keep a penny."

Speechless, he could only gape at the artist with a look of utter astonishment. Amazement couldn't even begin to describe what this news made him feel. Right on the heels of amazed came a phalanx of embarrassment, then shame. The parade ended with a spike of nausea that he had to swallow down thickly as the depth of his misjudgment of Temperance Brennan was exposed.

Smirking, Angela reached out to gently push his jaw closed. "Now you're starting to see what we see. If you want to apologize, she's probably either in Limbo or at the shooting range. If she's in Limbo, she's close to forgiving you."

Still recovering from her shocking revelation, Booth sent her a blank look. "Limbo?"

The artist shrugged. "Brennan prefers 'modular bone storage,' but I think Limbo is more poetic. The Jeffersonian has thousands of unidentified bodies waiting for identification or authentication. Limbo is where they wait."

He stored that knowledge away with the other nuggets of trivia Angela was letting fall today. "So she goes there to calm down," he surmised.

Angela laughed. "She's always calm, except where you're concerned."

Off his startled expression, she continued. "If she's at the shooting range, it's probably you she's thinking of shooting. Better put on a bullet-proof vest before you approach."

Wearing a mischievous grin, she left him standing in her office with a riot of thoughts tumbling through his head. Foremost among them was the sinking realization that, in order to win back Temperance Brennan, he was going to have to become some kind of saint. But he wasn't ready to be a saint, not yet.

~Q~

Booth found her standing with legs stiff, arms braced, and a semi-automatic pistol bucking gently in her hands. Brennan sent five shots straight into the human-shaped target's center of mass, punching a neat little cluster of holes into the 'bulls-eye' at fifty yards. Booth watched silently until she was finished, impressed despite himself.

"Thought I might find you here," he finally announced when she lowered the smoking pistol. He didn't add that he'd known there was only one other place to look, and he'd checked Limbo first. That she was shooting meant she wasn't in a forgiving mood. Disappointed and apprehensive from Angela's warning, he'd decided to go on the offensive. She couldn't attack if he attacked first.

"You know, you being a good shot, an expert in three martial arts, it's just your way of dealing." Brennan removed her hearing protection as Booth sauntered closer, concluding sarcastically, "Who knows better than you, how fragile life can be."

She refused to face him, but her challenge drifted back over her shoulder. "Maybe an Army Ranger Sniper who became an FBI homicide detective."

Booth pursed his lips, suddenly feeling flattered. "Ah. You looked me up, huh?"

He stepped boldly into her cubicle, gesturing to the pistol she'd laid on the bench. "You mind?"

"Be my guest." She slid a different gun his way, a snub-nosed revolver.

"Thank you," Booth murmured. Lifting the small handgun, he sighted and shot. The bullet flew wide, strafing the target's forearm. He winced, feigning dissatisfaction.

Brennan smirked, knowing he'd missed because of her, intentional or otherwise. Either way, she counted it a victory. Laughing, she cooed, "Were you any good at being a sniper?"

Booth leaned closer to her, leaving her bait untouched. "A sniper gets to know a little something about killers. Senator Bethlehem? He's no killer."

Brennan turned toward him, chin tipped challengingly. "Oh, and Oliver Laurier is…."

"The way I read Laurier, he's unhinged." He tipped closer to Brennan, closing the distance until mere inches separated them. Whispering, he taunted, "that makes him dangerous."

"That'd be your gut telling you that, correct?" Her eyes were flashing again like sunlit glass. A mocking smile tugged at her lips, dragging his gaze briefly to her mouth. Memories of those lips sliding against his darted through Booth's mind, the taste of Tequila and paradise still lingering on his tongue. With iron resolve, Booth forced his attention away from her tempting and oh-so-irritating mouth and back to putting her in her place: the lab. She didn't belong in his world and it was high time she got the message.

"You know, homicides, they're not solved by scientists. They're solved by guys like me, asking a thousand questions a thousand times, catching people telling lies every time."

He pushed in closer still, raising his arm to block her exit. He bored into her eyes, wide and glinting with intelligence. Her pupils expanded, her body flooding with adrenaline in preparation for the battle of wits and tongues they were engaging in. But she didn't flinch or look away, he noted.

With mock sympathy, Booth concluded, "You know, Bones, you're great at what you do, but you don't solve crimes. Cops do."

Most people retreated when someone stepped that deeply into their personal space. Brennan leaned back against the wall but didn't back down. Of course she wouldn't, he mused. 'Most people' weren't a former foster kid with three PhDs, a scientist who knew enough karate to break a judge's nose and bring down a Homeland Security agent. Booth was getting the feeling that Temperance Brennan didn't back down from anything. As much as she was pissing him off at the moment, he grudgingly had to admire her spunk.

"Cleo Eller died on a cement floor sprinkled with diatomaceous earth. Traces of her blood will still be in that cement."

The rasp of her alto voice skated over his skin, sending shivers everywhere. How was it possible the woman's voice turned him on that much?! Once again, his eyes fell to her lips, and he was sorely tempted to try his luck kissing her again. Only the presence of multiple handguns within her furious reach held his baser urges in check. Instinct told him she wouldn't hesitate to shoot if he dared to touch her just now.

"One of us is wrong," Brennan nearly whispered. "Maybe both of us."

She cocked her head to the side, the arrogant half-grin that still haunted his dreams ghosting across her lips. "But if Bethlehem wasn't a senator, you'd be right there in his basement looking for that killing floor. You're afraid of him."

Booth felt his desire melting back into fury. She was calling him a coward?

Brennan smirked, knowing she was getting to him. Her people skills might be lagging, but for some reason she found it ridiculously easy to find and push Seeley Booth's buttons. "Your hypothesis is that squints don't solve crimes and cops do."

Again that sexy, arrogant grin. "Prove it," she dared him.

Again, that raspy whisper that made him want to throw her on the ground and take her right there. "Be a cop," she taunted, and slipped away.

Booth watched her strut away, her hips swaying just a bit more than usual. Somehow she'd managed to grab her two handguns while he was busy getting lost in her voice and lips. He suspected she'd known that. Gritting his teeth, he drew his own service pistol and leveled two shots to the head of Brennan's abandoned target. For a half second, he'd almost imagined it was Brennan; she pissed him off that much.

Turning, he found her gathering up spare ammunition and replacing her firearms in their carrying case. Rather than looking triumphant, she looked … unsettled. There's more to her than you think. His talk with Angela tempered the simmering irritation just enough that he decided to try again. Thanks to Angela's intervention, Brennan was a puzzle that he was becoming determined to solve.

"I read an interesting newspaper article recently."

Brennan's attention remained on her task but by the stiffening of her shoulders, he knew she was listening.

"You started a scholarship in Jemma's name."

The movements of her hands slowed, stopped. She held very still for a long moment. When her face lifted to his, she looked as wary as a doe during hunting season.

"Why'd you do that, Bones."

"Don't call me Bones," she retorted, the response automatic.

He stepped closer again. "Why?"

Her gaze slid sideways, her lips compressing. "The idea for my book was a result of Jemma's death. It didn't seem right to profit from her family's tragedy." She shrugged, trying to deflect further discussion.

Slipping one finger under her chin, Booth lifted her face back up to his. He studied her, the tip of his thumb stroking her chin absently. "You surprise me," he mused.

As a soldier, as a sniper, as a gambler, as an investigator, Booth made his living reading people. He could look at a person and see right into the heart of them, read them like newsprint. Brennan was a heavy text filled with foreign, incomprehensible words. The fact that he couldn't figure her out lured him as nothing else could. He knew she wasn't doing it intentionally, which made her mystery all the sweeter. The only thing constant about Brennan was her unpredictability.

She jerked her face loose, surprising him again by retreating, where before she had stood her ground. "You don't know me."

"I know," he agreed. "That's why I find you so fascinating. I know people; but I don't know you. You ever gonna let me in?"

Her brow furrowed, confusion clouding her eyes. "I don't know what that means. Let you into what."

"You," he whispered.

Shock stole the color from her cheeks. Sputtering in outrage, she began telling him just what she thought of that notion. "You conceited, supercilious—"

Booth threw back his head in laughter. "Metaphorically, of course. Simmer down, Bones."

"Don't call me Bones!" She slammed the last pistol into the case, snapped it shut and stormed out of the shooting area.

Watching her leave, Booth laughed at himself. She ticked him off, turned him on, spun him around and left him dizzy. He could see he was having the same effect on her—Angela had all but confirmed it. "She's always calm, except where you're concerned." Whatever she did to him, knowing he was doing it to her also just made it so much better.

The chemistry he had with Brennan had him thoroughly enthralled. Her lips had brought him to the very gates of heaven, and 24 hours later her fist had slammed him down into pain and confusion. She was spitting fire one moment and dishing out breath-taking generosity the next. She was dangerously sexy and yet hopelessly naïve; so clever she could look at a hazy image of a bone and identify a person, yet so ignorant of reality that she thought her word alone was enough to issue a warrant. The woman was a walking maze of contradictions.

Most of all, though, she'd been right. She'd been right about Jemma Arrington's characteristics and cause of death. She'd been right about the judge's nose. She'd been right about the x-ray consult as well, giving him a weapon and a killer. Grudgingly, he had to admit she was probably right this time too, at least in her assertion that the killer had done everything to conceal Cleo's identity. But was it the senator?

Booth considered the gauntlet Brennan had all but stripped off and thrown in his face. Prove it. Be a cop. She wanted him to search a senator's house. Booth retrieved the target they'd pierced together, noting her tight group in the heart and his deadly twins in the head. Head and heart. Together, he and Brennan made a potent team at the shooting range. How would they fare in the field?

With a sigh, he pulled out his phone and dialed the number of a sympathetic judge he knew. What better way to prove himself—and Brennan wrong—than getting the damn warrant to search Bethlehem's house.

~Q~

Author's Note: While it looks like I may have taken liberties with Brennan's generosity, in actuality I am referencing a certain newspaper article that appeared quite briefly on-screen in season seven's Crack in the Code. The article mentions Dr. Temperance Brennan as having donated to a scholarship. The article is titled, "Opera Scholarship Founded to Honor Slain Singer." The part about her donating all the profits from her book comes from me. However, I wouldn't be surprised if she did something that generous, given she used profits from another of her books to rebuild a washed out bridge in a small town (which would cost millions!), and she also most likely donated generously to the scholarship fund that her intern Wendell Bray depended upon.