On the day that six-year-old Dillon Crane was abducted, the FBI had already uncovered the desecrated remains of three young boys, and Brennan was trying to focus on the minutiae of their bones instead of taking a step back to view the bigger picture, because that meant trying to fathom an incomprehensible act of savagery. The rigours of the investigation were taking a noticeable toll on the team, but there was no reprieve. Their usual banter and good humour suddenly seemed jarringly inappropriate, and the increased sense of urgency following Dillon's abduction was pushing Booth towards breaking point. All of the Squints – including Brennan herself – had fallen foul of his frustration at some point, but none of them had succumbed to a defeatist mentality. They couldn't bring themselves to envisage what would happen if they didn't make the breakthrough in time to save Dillon from what was destined to be a horrific fate. In the past, they always had.

In the absence of Zack, Brennan performed all of the groundwork, but her facade of clinical detachment became increasingly difficult to maintain when examining the broken fingers, shattered jaws, cracked ribs and fractured pelvises of the tiny victims, all of whom were less than eight years old. It was immediately apparent that the innocent young boys had been targeted by the same depraved perpetrator, who held them for days prior to disposing of their battered and broken bodies. But the bastard didn't prolong their misery in the hopes of extracting a ransom from their distraught families; he used them purely for the purposes of his own gratification. The first two sets of remains were too decomposed to be subjected to an autopsy, but when Cam finished examining the cadaver of five-year-old Bobby Reynolds, the latest victim to be unearthed, her devastated expression had voiced the unspeakable.

Angela had burst into tears, running to the bathroom, and a visibly shaken Hodgins was hot on her heels. Cam excused herself shortly thereafter, and had to down two measures of scotch before regaining some sense of equilibrium. Booth maintained a stoic silence, but his posture was rigid with tension and Brennan had been in the process of tentatively approaching him when he suddenly lashed out, kicking a nearby chair and sending it hurtling across the room. She tried to conceal her shock, but with little success, and Booth regarded her with an incomprehensible expression before stalking away. It was only then that Brennan allowed the tears to fall, but they stopped almost as soon as they started. She couldn't allow her objectivity to be compromised. Less than two minutes later, she was back in the lab, filled with a renewed sense of determination, despite the fact that she had endured almost thirty-eight hours without sleep.

By the time Booth returned, Brennan had determined that the perpetrator had inflicted most of the victims' injuries with his bare hands. She was able to calculate the span of the appendages in question, as well as the fact that he favoured the use of his left hand. With Hodgins's help, she also managed to establish the exact make and model of the baseball bat and the brand of pliers that had inflicted the more substantial damage, as well as the knife that eventually ended the victims' suffering. Her hands shook slightly as she handed her findings to her partner, and she glanced up in surprise when Booth gently ran his thumb along the length of her knuckles, before leaving to pursue the leads.

Unfortunately, there was nothing distinctive about the weapons in question – the pliers could have been purchased from any DIY store, the knife was from a cheap kitchenware set that had almost sold out owing to its popularity, and the baseball bat seemed to be a fixture in every kid's backyard. In the absence of the elusive weapons themselves, tracing their origin was fruitless.

Trying not to be affected by the increasing sense of desperation that permeated every inch of the lab, Brennan provided Booth with a physical profile of the murderer, including an approximation of his height and weight. The Angelator assisted them in deducing his modus operandi, but even still, that hadn't been enough to help them to identify a suspect – not when there were no discernable links between the victims. They didn't attend the same school, participate in any extra curricular activities together, or live in the same neighbourhood. Their parents were strangers, had never encountered each other in the course of carrying out their diverse professions, and none of them appeared to have amassed any enemies along the way. Booth had his whole task force interviewing everyone the boys had ever come into contact with, but there were no connections, no witnesses, nothing. Every avenue became a cul-de-sac, and every dead end drove Booth further towards the brink of despair.

It was 2am on Thursday morning when Cam and Hodgins argued their way into an epiphany. The bugs and slime guy had been perturbed by the incongruous trace evidence on what was left of the victims' decayed clothing, but when Cam stopped being supportive and started piling on the pressure, they finally got their breakthrough. Booth was sprinting towards his SUV within a matter of seconds, and Brennan was running right alongside him. The knowledge that they finally had the information they needed instantly eradicated the effects of chronic sleep deprivation. They might not have known the 'who,' but they finally had the 'where,' and that was a blessing they were more than willing to accept. Still, it was going to be a delicate operation, and dealing with an unknown entity made the situation even more volatile. Booth had the foresight to call for backup before they arrived on the scene and, seeing him flanked by twelve of his fellow Agents - knowing he was wearing a bulletproof vest - for once Brennan heeded his solemn plea for her to stay in the SUV. And, despite feeling completely inadequate, she had. At least until the piercing sounds of the gunshots subsided. Waiting for Booth to emerge unscathed was agonising, but when he didn't appear after ten minutes, all of her previous vows were swept away in a torrid rush of adrenaline.

In hindsight, she realised the Agent guarding the door was trying to spare her a lifetime's worth of trauma by denying her access to the scene. However, having already caught sight of her partner slumped on his knees, Temperance's response to the robust man's chivalry had been to forcibly push her way past him. Her first thoughts were that Booth had been injured, and at the time that was the worst scenario she could have possibly envisaged.

Then she realised that her partner was cradling the lifeless form of Dillon Crane in his arms, giving the impression that he was trying to shield him from the unspeakable horrors he had already endured. For the first time since she could remember, Brennan was looking at a dead person who hadn't been reduced to flesh and bone. Dillon was battered beyond all recognition, and his frail frame offered an excruciating insight into how much he had suffered prior to his death, but the innocent boy he had once been still shone through the blood and the bruises. They were too late to offer him salvation.

Brennan's eyes welled with tears as she watched Booth murmuring an inaudible apology into the deceased boy's filthy hair, before gazing up to the Heavens with an agonised expression that clearly begged the question, 'why?' He was rocking Dillon against him with infinite tenderness, and Brennan wondered if he was aware of the attention he was gathering. She wanted to shout at the other Agents to stop staring, but when she took the time to study their expressions, she realised several of them were on the verge of tears. There was no recrimination in their empathetic gazes, even though Booth was effectively contaminating evidence. She supposed that was because they no longer had to worry about catching the monster responsible for this atrocity.

As Brennan's eyes adjusted to the darkness, she could make out the crumpled corpse of a white male, who appeared to be around 40-45 years of age. She wanted to see his face; she wanted to know whether she was capable of identifying the kind of man who could commit such horrific acts of violence against defenceless victims, but all she saw was the blood-spattered bullet hole between his eyes; a hole that had been drilled with lethal precision. Once again, her eyes flitted towards her partner and, as if to confirm her suspicions, an Agent chose that moment to gingerly pick up the gun that Booth had set aside and place it in an evidence bag. As Booth continued to gaze up at the ceiling, praying for the boy's lost soul to find its way home, Temperance wondered if her partner realised that he had been the one to exact divine retribution for Dillon Crane.

Until now, Brennan had never thought it was possible for your heart to break. People spoke of this ludicrous phenomenon as though it was almost commonplace, and every time she heard the trite expression, she inwardly rolled her eyes. 'A broken heart' was a metaphorical assertion that was steeped in melodrama, usually for the purposes of attention seeking. However, as she watched several Agents gently trying to coax Booth into relinquishing his hold on the young boy, Brennan was finding it increasingly difficult to rationalise the wrenching ache in her pounding chest, and respiration no longer seemed like a natural process. Sucking air into her burning lungs had become an arduous task, and she found herself wondering whether failure had the capacity to weigh down on you like a heavy and unyielding mass. It was omnipresent; inescapable, and every one of her shallow breaths seemed to exacerbate the burden. She swallowed intermittently in a bid to obliterate the prominent lump in her throat. It was threatening to choke her, and even though asphyxiation would probably be a welcome reprieve at this moment in time, she knew her own pain was negligible in comparison to Booth's. Dillon was the same age as his son, and she wondered if he was imagining what it would have been like if Parker had been taken in his place. She could understand why he was so loath to let the young boy go.

At some point, Deputy Director Cullen had arrived at the scene, and Temperance watched as he hesitantly approached her partner, laying a hand on Booth's shoulder and offering his commiserations in a surprisingly kind tone. Booth, however, seemed to be lost in a grief-stricken reverie, and she could see that Cullen's words were failing to register. The aging Deputy-Director picked up his cell phone, and when she heard him utter the words 'Dr Sweets,' the thrumming of her heart started anew and she knew she had to intervene.

"Booth?" Her hand was trembling when it came to rest on the nape of her partner's neck, and to her surprise, Booth immediately turned to face her. She should have questioned her ability to reach him when no one else was able to elicit a response, but instead she stifled a gasp when she saw the raw pain characterising his haggard features.

"You shouldn't have to see this, Bones. Go and wait in the car. I'll be out in a minute."

His tone was little more than a strangled whisper, and even though she had been trying desperately hard not to glance at Dillon since establishing her newfound proximity to his crumpled form, her partner's words seemed to compel her to look downwards, and she couldn't suppress a cry of anguish at what she saw. The little boy's blackened face was frozen into a tableau of terror, and for the first time in her life, Temperance understood the compulsion to flee from a crime scene and violently regurgitate the contents of her stomach. Instead, she, too, sank to her knees, and watched as Booth's protective grip on the little boy began to waver.

"I'm not leaving without you, Booth."

Her partner was still feebly clutching Dillon's mangled hands, and it took all of Temperance's willpower to retain her composure as she gently prised his fingers away. "You need to let go," she whispered, chafing his knuckles with her trembling thumb as she gradually replaced Dillon's hands with her own.

He gave her his undivided attention then, and his expression clearly conveyed that the young boy's death wasn't something he would ever be able to let go of. She nodded almost imperceptibly to indicate that she understood, and then buried her head in his shoulder, feeling the vibrations running through his tense physique as he drew in a hitching breath.

"Agent Booth?" A young Agent tentatively approached them, carrying a body bag that looked painfully small.

Booth eyed him warily, and then nodded, finally gathering the resolve to lay Dillon's prostrate form onto the cold cement floor. His fingers gently smoothed back the little boy's hair, and he leant over him for what seemed like an eternity before eventually finding the strength to drag himself to his feet. Seemingly unaware of the fact that he continued to clutch Brennan's hand, Booth made his way towards Cullen, but the Deputy Director began shaking his head before he'd even had the opportunity to open his mouth.

"Your statement can wait until later, Booth." Cullen clapped him on the shoulder in a fatherly gesture of support. "You busted your ass on this one and I've got twelve witnesses who are adamant that the bastard had it coming." He sighed, rubbing his face tiredly. "Go home and get some rest, and I don't want to see you back at work until you feel up to it. You got that?"

Booth nodded gratefully and managed a weary half-smile, but Brennan wasn't the only one who noticed his lingering distress. As Booth made to leave, Cullen seized his forearm and eyed him intently.

"Don't even think about blaming yourself, Booth. The only person responsible for that poor kid's demise is that sick fuck over there." He glanced towards the corner of the room with eyes that were blazing with contempt, and then turned to Brennan, favouring her with a slight smile that she half-heartedly returned. "And that goes for you, too, Dr Brennan. You and your squints did everything you could. We all know that."

"Thank you, Sir." Booth's jaded tone clearly conveyed that he had found little solace in his boss' reassuring words, and he tugged lightly at Brennan's hand, discreetly tilting his head towards the door.

Brennan offered Cullen a polite nod, before focusing all of her attention on keeping pace with her partner, who was power-walking through the ramshackle warehouse at a speed she was struggling to match.

She didn't know what to say when they finally reached the SUV. For a moment, Booth leant against its exterior as though it was the only thing keeping him standing, and then he slid downwards until he was crouching on the balls of his feet, releasing her hand so he could bury his head in his arms. Shielded from the view of prying eyes, for one terrifying moment, Brennan thought her partner was going to cry, and the prospect made her own eyes well with unshed tears. Booth had reined in his emotions remarkably well, but she knew it was only a matter of time before he broke down completely. She had never seen him so utterly defeated before, and she was scared that her social inadequacy would only make matters worse. She sank down besides him, laying a hand on his forearm and trying to stroke away the tension she found there.

"I'm so sorry," she murmured, but the sentiment seemed painfully inadequate. Was it even the right thing to say? It was what they told the distraught families whose loved ones she had identified, and it was what Booth said to her when Ripley was put down. Although the words themselves hadn't made her feel any better, the fact that he so obviously meant them had, and she hoped they offered him some small measure of comfort.

He looked at her then, and there was a fleeting spark of warmth in his otherwise deadened eyes. And then he asked her if she was OK, as though her pain somehow took precedence over his own, and she shook her head in disbelief, throwing her reservations aside and pulling him into a fierce embrace. Her lips grazed the stubble on his unshaven cheek, and she pressed them lightly against his temple, barely noticing when their combined weight brought them to their knees in the damp, muddy undergrowth.

"Bones, I'm filthy," he protested weakly, but she was heedless of the blood staining his clothing and hands, immune to the pervasive stench of terror and death that clung to him, completely obliterating the scent of his cologne. When he realised she wasn't going to recoil in horror, Booth's arms inched around his partner's slender waist, and he tried not to think of Dillon Crane as he cradled her against him. She was cold, and trembling, but she was alive, and he buried his face in her hair, inhaling the familiar fragrance of her shampoo and allowing it to soothe his sickened senses.

Booth was visibly exhausted, but Brennan's breathing became a little less laboured when he started to relax against her. They held each other tightly for several minutes, but Brennan's bloodshot eyes flew open when Booth's back went rigid and he abruptly released her, hauling her to her feet before she even had the time to wonder why.

"Get in the car," he barked out, and something about the brittleness of his tone told her that now wasn't a good time to question whether he was fit to drive. For a moment, she was too shocked to function, but the knot in her stomach gradually loosened as she followed the direction of Booth's harried gaze. Cullen clearly hadn't bothered to inform Sweets that he was no longer needed, and the therapist was advancing towards them with an inscrutable expression. Though she was inwardly concerned about how much he might have witnessed, Brennan didn't need to be told twice. Sweets had barely managed to advance three feet before Booth turned the ignition and sped away, and if it hadn't seemed so horribly inappropriate, Brennan would have smirked at the therapist's stunned countenance.

It was another ten minutes before either of them spoke.

"I shouldn't have shouted at you like that. I'm sorry." Booth's jaw was clenched tightly, but he loosened it for long enough to heave an aggrieved sigh. "There's just no way I could've dealt with that sanctimonious little shit back there."

"I know," Brennan murmured, studying her hands attentively, "It's OK."

Silence descended again, and Brennan gazed out of her window with unseeing eyes. When they reached the street housing her apartment complex, her heart began to hammer disconcertingly against her chest, and her stomach sank when Booth failed to cut the engine upon pulling into her parking lot. She should have been relieved. This was her get-out clause; she had enough emotions of her own to process without adding her devastated partner into the equation. Booth had spent the duration of the journey carefully cultivating an expression of detachment, but his haunted eyes told an entirely different story, and she knew it wouldn't take much for his façade of self-possession to shatter into thousands of irreparable pieces. The thought of him falling apart in her less-than-capable hands terrified her; to the extent that she wanted to say goodnight and run in the opposite direction, but something was stopping her from utilising her 'get out of jail free' card.

"You should come up," she offered, and Booth glanced at her in surprise. He clearly hadn't been expecting the invitation, either.

"I think I'm just gonna go home, jump in the shower and then crash, Bones." He stared at his bloody hands with an unhealthy fascination, and refused to meet her concerned gaze. "I don't really feel like talking tonight."

"Neither do I," Brennan confessed, giving him a tentative smile. "But we can maintain a vigil of silence together, right?" She unfastened her seatbelt and leant over her chair, fumbling her way around the back seat until she found her partner's overnight bag. Booth always kept a spare set of clothes in his car, because they never knew when they were going to be called to a crime scene. "You can shower and change at mine," she ventured, regarding him hopefully, and he slowly shook his head.

"It's OK, Bones, really. I'll be fine."

His voice cracked on the last syllable, and Temperance looked at him sharply. She wished she knew how to ease his pain – Booth always knew the right thing to say, the right thing to do. He knew when to give her some much-needed space, when to bring her Chinese takeout, and how a small plastic pig had the capacity to make her smile again. She was comparatively clueless. She reached for his hand, squeezing it tenderly. "You're not fine, Booth," she said softly, regarding him intently. "Even I can see that you're extremely upset."

"OF COURSE I'M UPSET, BONES!" Booth yelled in an unexpected tirade of anger, wrenching his hand away from her. "And I really don't think you're the best person to be educating me about how to deal with my emotions, OK?"

Brennan recoiled as though she had been struck. Clearly she had completely misjudged the situation and her presence was doing more harm than good. "OK," she murmured, choking back tears, and she fumbled hastily in a bid to open the door. She stumbled out of the car, swiping furiously at her eyes, and had almost made it to her door before Booth finally caught up to her. The first time he called her given name, she ignored him, but then he was clasping her shoulders and saying it again, only this time it was punctuated by a heaving sob...