"And I'm gonna learn Mandrine. I've decided." The little boy told his father confidently, shovelling another chunk of s'morlette into his mouth. His words were muffled as his breakfast collected in his cheeks. Melted chocolate gathering at the corners of his mouth.

"You mean Mandarin, as in the language?" Castle was unperturbed by the statement as he bent over the stove, spatula in hand; just last week the boy had announced he was going to learn how to do karate. Which, as it turned out, had merely been an afternoon of him running around the lounge in his bathrobe with a comically serious expression repeatedly kicking the couch.

"Yep!" Felix popped the 'p', following it up with a confident, chocolaty grin.

"You are, huh?" Rick jostled the pan in his hand, sliding the s'morlette from rim to rim.

"Yeah, my friend Cal speaks it. He said I should learn it so we can have super-secret conversations. Like spies!" Felix added excitedly.

"Sounds awesome, Dynamo." Castle said, distracted as he scraped the spatula he was holding across the base of the pan, flipping its contents onto a plate.

"What sounds awesome?" Kate Beckett appeared from the bedroom, practically gleaming she looked shiny, already in a crisp dark pant suit with a white shirt underneath.

Before Kate could get close enough to kiss him Felix had jumped from his stool and scuttled over to his father.

Kate froze, heart plummeting, her stomach flipping in disgust. Had her own child just… run away from her?

"Daddy! I need my stool!" The boy bounced on the balls of his feet impatiently.

"Uh…" Castle spun around, seeing the blue, plastic booster step tucked in the corner at the base, he kicked it over to Felix.

The kid promptly copied his dad, managing to nudge the step toward a nearby section of the counter with the force of his foot. He clambered up speedily, pulling aggressively on the tap, proceeding to scrub his breakfast-coated hands and face. Then he grabbed a dry washcloth, running it roughly over his mouth.

"Felix?" Beckett took a step toward him, still unnerved.

Felix hopped back down and, much to Kate's relief, sprinted over to his mom. He wrapped his arms around her midsection, nuzzling into her, she could feel his breath on her lower abdomen. His hands were clutching at her blazer as tight as a vice.

"Felix, what was all that?" She asked tentatively.

"So my cuddles aren't mucky." He said it like it was obvious, his face still pressed against her.

"Seriously," Castle raised a brow jovially as he stabbed a fork into his s'morlette, "One day with Alexis in charge and suddenly he's all prim."

Felix only gripped his mother tighter at the mention of her absence.

He was being needy. Felix was a lot of things; stubborn, creative, precocious, maybe a little loud, sometimes a bit moody, but he was rarely needy. Until the age of 5 the kid had been surrounded by adults all day almost every day, except for the few hours a week he spent in day-care. His mother had a full-time job that forced her to be absent at odd hours. There had been no other children to play with, and even with Castle as a father there'd been plenty of the times the boy had spent hours entertaining himself as his dad wrote. As a result Felix was resilient, and fiercely independent.

Kate knew what this meant. It meant she was in too deep. Felix didn't care about the hours, sometimes the days away, he was used to that. It was the distance in his mother's eyes when she was looking right at him that told him something was up. He'd seen it this morning when he'd woken up to find her home, and already making coffee in her pyjamas.

"Mom?" He dislodged sleep from his gritty eyes as he descended the stairs, barely awake, and still in his sleepwear; a superman top matched precariously with pants covered in brightly-coloured dinosaurs.

The earthy, dark smell of coffee was hanging in the air. The fan on the stove whirred away softly, sending the heady smell scattering over to him. Felix gripped the banister as the woman spun round to regard him.

"Felix, you're up." Her voice was warm, always comforting, like a mothers voice is meant to be. A tone of speech she employed just for him.

"Mommy?" His feet led him down the last couple of steps, quicker and faster, almost slipping in his hurry.

She abandoned her coffee mug and strode over, picking him up in one clean scoop, placing him on her hip, holding his warm body as close as possible to hers, "Hey baby, I missed you. I…" Her mouth parted as if to continue, but then it closed. Silence.

Felix's forest green gaze met her hazel one, full of far too much for such a young child.

The little boy placed his small hand on her neck, his fingers gently finding her pulse. He remembered his dad telling him, 'See. Put your fingers there. Can you feel it? That's your life, Dynamo. That's your life. It's beating underneath your fingers.' Felix did it almost involuntarily. The look in his mother's gaze was one of love, always, but it was veiled. Guilt clouded, building a wall, drawing a curtain between mother and son.

A dent appeared between Felix's eyebrows, "You're here, Mommy?" He didn't falter, didn't hesitate, his features hard and set like Castle's were when he was hurt, when it was deep and personal, when she'd hurt him. It'd been a long time since she'd seen that look, but it was an impossible one to forget.

The words threw Kate. She recalled her own father's words of wisdom from when Felix had been a newborn, wailing red-faced in his inexperienced and fearful mother's arms, 'Kids can sense things, Katie.'

Kate's lips parted, "I…"

She needed to solve this, but she was hurting Felix in the process. Every time she saw him a small voice in the back of her mind asked, 'what if?' She squeezed her eyes shut, trying to banish the thought from her mind, but its strength only grew. 'What if Felix was Barney?' 'What if I died?' 'What if Felix was alone?' …

'What if he ended up like me?'

Looking inside she could see it, that tiny part of herself she'd tried put to bed years ago after it nearly tore everything apart. The part of her that just couldn't give up and move on. Katherine Beckett was as stubborn as they came, but it wasn't about pride, it was rooted in failure… the heavy sickening feeling in the pit of her stomach, sitting across from a grieving child to tell them you couldn't do it, you couldn't catch the person who ruined their life.

Montgomery had once told her, in an intonation that to this day stayed with her, sending chills across her spine, 'We speak for the dead. That's the job. We are all they've got once the wicked rob them of their voices. We owe them that. But we don't owe them our lives.'

She'd never had a chance to ask him… What about the living? What about those that have to go on knowing every day that somewhere out there that wickedness walks free? A life for a life saved, was that worth sacrificing? She didn't want to think of Felix obsessing, risking, and losing what she had.

"Are you okay?" Felix's question reached her, arms still secure around her, face upturned now as his chin rested against her stomach.

"Kate?" Rick said, silently reiterating the question from behind the kitchen counter.

She ran her fingers slowly through Felix's dark hair, her other hand coming to hold his jaw, a thumb running gently over his rounded cheek.

"Yeah." Her voice was barely more than a whisper. She knelt, his arms loosening to let her, "We have to go now."

"I know." The boy said, blinking, lips pursed and down turning.

"I love you." She took him by the upper arms and pulled him in, pressing a lingering kiss to the lobe of ear, his temple, his brow.

…

"Hey." Sorenson flinched at the sight of her, they'd barely spoken since he'd accused her of being too emotionally invested in this case, and he wasn't completely sure where he currently stood. The conversation on the journey home yesterday had consisted mainly of short, calculated 'can you pass that's and 'what the time's, and nothing more. If Castle had noticed, which Beckett suspected he had, he didn't say a word.

As they'd reached the floor, stepping off the elevator, just moments ago, upon seeing Sorenson, he'd mumbled out a quick excuse to give her a minute with the FBI agent. Heading over to make coffee in the break room, despite them having had a cup not more than an hour ago.

"Hey." Beckett's voice nearly cracked as she spoke but she covered it up with a sigh, perching on the edge of the desk beside him.

They sat in the quiet, the light hum of the precinct coming to life around them. Each person pretending to read the murder board in front of them.

"Kate I-" Will finally started.

"I need to apologise." Beckett spoke over him, rubbing her brow roughly, "I shouldn't have reacted the way I did."

"No," Will's teeth were gritted in acceptance, "I stepped over the line."

"Maybe," Kate sucked in a breath, standing up, folding her arms in tightly, she dragged her gaze from the floor to look him in the face, "but you did it to tell me something I needed to hear."

Will waited, jaw squared.

"I am too close to this." Kate nodded, turning to observe the murder board. The face of little Barney Ryder stared back at her. It was a school photo, there was a wide smile reaching all the way up to his glittering blue eyes.

"I want to protect him too you know." Sorenson said gruffly, standing up to join her.

There was a guarded nature to his tone, an element that promised something more than he was telling her. He was invested in this case too, more than she could know.

"Never doubted it." This time she looked him in the eyes with no apprehension.

…

"Alright, ladies and gentlemen. Hold onto your socks." Ryan announced with vigour, striding over, Esposito at his side, to where the rest of the team were huddled around the murder board waiting. "The DA's office finally got round to signing off on the witness protection files."

"So we finally know who Fiona Ryder actually is?" Castle inquired anxiously, fingers itching to crack open the promising, federally stamped file in Ryan's grip.

"And that's not the best part." Espo was quick to tease, nudging Castle with his elbow.

Sorenson leant back against Beckett's desk, quietly enjoying the scene playing out in front of him.

"Yeah. No doubt, you're going to love this one Castle." Ryan agreed, joining in.

"Definitely up your street, Bro." Esposito nodded knowingly, supressing a grin at Castle's frantic and expectant stare.

"Oh God, please put him out of his misery." Beckett rolled her eyes. Teasing Castle was always fun but she was nearly as desperate as he was to find out what the contents of the FWP file was.

"Two words:" Ryan paused to whip a picture out the file and slap it on the murder board, "Mrs O'Doherty."

The old photo looked to be a good seven years old. Fiona Ryder was younger, barely 23 years old, wide blue eyes and shorter hair that reached to hover just above her shoulders. It was difficult to determine the attractiveness of a corpse, the pallid nature of their skin, the blank eyes, it all made it hard to imagine them as once beautiful. But, in this image, in her youth, Fiona Ryder had been very, very beautiful.

"Specifically," Esposito furthered, "Mrs Aislin O'Doherty, maiden name Maguire."

"O'Doherty?" Sorenson stood sharply, as if shocked, moving closer, "I know that name…"

"The O'Doherty family," Castle spoke with the sure voice of a man who was well-versed in his New York mobsters, "They were a very successful off-shoot of the Westies."

"Were?" Sorenson picked up on Castle's use of past tense, concocting a story in his mind of their fall, and Fiona's part in it.

"'Mrs?'" Kate repeated Ryan's careful choice of address, "She was a wife of one of the Westies?"

Espo scoffed, "Not just any one of the Westies. Nine years ago she married Sammy O'Doherty Junior. Heir to the whole shebang. Then she copped him out along with a load of his cronies just over six years ago. She had enough damaging evidence to take down half the family. Got Sammy locked up for 7 years supposedly."

"Supposedly?" Sorenson turned to regard Javier.

"He got out on a technicality just over a year ago."

"Long enough to find Fiona, especially with his resources. The Irish Mob have connections across the US, maybe even moles in the government." Beckett added.

"And I'm guessing Mr O'Doherty was the type to hold a grudge?" Castle's expression was grim.

"That's not all." Ryan drew another photo out of the file to place next to Aislin. It was of a young man, generically handsome but for a strange bump in his nose that told the tale of a desperate fist fight followed by the refusal of medical attention. His dark eyes were a murky green, mouth set in an angry line. Short dirty blond hair sprouted thickly from his scalp. "Based on our timeline… it's safe to assume Fiona… Aislin, sorry, was still married to Sammy when Barney was conceived." He finished, delicate in his demeanour.

"It all makes sense," Castle murmured, moving closer to the board, "Fiona knew this was going to happen, she knew she was going to have to run. She told Simon and they set up the plan to escape where the Westies couldn't ever reach them. That call on the Sunday was her telling Simon it was time." The writer marvelled over the surreal nature of the story. "And, of course Barney was taken, Sammy wouldn't kill his own son. He wanted his son, and he wanted revenge, that's what this is all about!"

"Okay, Sherlock, but why were they in Brownsville? That's not Westie territory." Kate watched her husband, amused, quietly revelling in his enthusiasm.

"I don't know, Watson, but I'm going to figure it out." Castle smirked at his wife playfully.

"Shouldn't Beckett be Sherlock," Espo rebutted, arms crossed, "Since, you know, she's the actually the Detective."

"And, let's be honest here Castle," Ryan slapped the man on the back in a gesture of solidarity, "You've always been the sidekick."

"I resent that." Rick shot back, shrugging Ryan's hand from his shoulder.

"Guys, I'm happy for you to discuss this in your own time," Sorenson re-joined the conversation, trying to keep his expression as stony as possible, "But right now we have a suspect to pick up."

…

"I didn't do it." Sammy O'Doherty Junior leant loosely back in his chair, seemingly assured in himself. Sorenson circled him like vulture in the tiny interrogation room, letting Beckett stare him down from her position on the other side of the table.

The boy was a man now, a couple more lines around his mouth, his hair longer.

"What didn't you do?" Beckett rested against the glass, arms folding.

On the other side Castle and the boys watched intently, taking note of every twitch of O'Doherty's face.

"I don't know." Sammy shrugged, "Whatever it is you dragged me down here to accuse me of."

"Murder." Beckett answered shortly, she had a feeling the best way to get through to this guy was through straight-forward talking, and quickly, before he pulled the 'I don't have to talk.' card.

"Murder?" Sammy's eyes widened, lips parting, "Look, I don't know anything about a murder." He looked a lot less relaxed now. Staring 25 years in the face will do that to you.

"Really, because you knew the victim." Sorenson stated, slamming the photo of Fiona Ryder, the former Aislin O'Doherty, down on the table in front of Sammy.

"Aislin?" Sammy brought his fingers to meet the image, "Aislin's dead?" The shock in his voice seemed real enough, but being a mobster's kid and being a good liar sort of went hand in hand.

"Nice try, Junior." Sorenson sighed. "You know when I was up in Boston I talked to Aislin's son's school. Someone mentioned a man matching your description hovering around the gates a couple of weeks ago." Will's tone was sharp, accusatory.

Beckett moved toward the table, settling in the seat across from O'Doherty, "So what happened, Sammy. The betrayal of her ratting you out to the cops, all whilst pregnant with your son, just too much for you to handle?"

The man scoffed, turning his gaze to the floor.

Beckett carried on, "Did you get angry? I mean, that's understandable, she took Barney away from you, didn't even give you a chance to know him. She got you locked up for six years of his life. Then when you track her down she's happily married, raising your kid with another guy, that's got to hurt."

"Okay, so what if I went to see him." Sammy hissed, "It's not a crime. I went to see if it was true, I got a tip off saying she had a kid old enough to be mine, so I went to check it out."

"Where's Barney, Sammy?" Sorenson said, jaw set.

"I don't have the damn kid, okay?" Sammy yelled, bring his fist down harshly on the table top, "And I didn't kill Aislin. I went to see her, that's all. I told her I didn't blame her for copping me out, she was manipulated, I knew that then and I know it now. I just wanted to know if the kid was mine. She explained that he wasn't, so I left."

There was a pregnant pause.

"Plot twist." Castle whispered to a transfixed Espo and Ryan as they watched from the other room

"You're… you're not Barney's father?" Kate's shoulders slumped. They just couldn't seem to catch a break in this case.

"No," Sammy looked between Sorenson and Beckett, noting their dubious expressions, "Can't say I was surprised, last few months before she ratted me out I thought she was having an affair, she kept sneaking out and avoiding me, but then I ended up in police cuffs so I figured that's what she'd been up to. Looking back… maybe it was both."

"Why'd you say that?" Sorenson finally settled down in the seat next to Beckett.

"Look, it's not me, but I know who the kid's dad is." Sammy leant a little further across the table, "The guy who sent me down, who turned Aislin against me. That bastard lawyer, Reilly Kane."

Sorenson scrawled down the name and promptly exited, the door slamming in his wake.

"Mr O'Doherty where were you last Thursday night between 11:30 and 12:15." Beckett was less and less sure by the minute that this was their killer, but she had to ask.

"Uh… a bar just off central park, with my friends, playing some pool. I can give you names… Jonah Locke and Freddie Hogan."

"Detective I'm afraid we're going to cut this short!" A short, dark-haired, ordinary-looking man in a crinkled black suit entered the room with vigour, the door slamming harshly against the wall.

"And you are?" Castle was at the door in a flash, a determined expression on his face. Ryan and Esposito crowded behind him, back up, as always.

"Anderson Kelly. Mr O'Doherty's lawyer," The man shot Sammy a short look, "and I'm advising him to say absolutely nothing from this point forward. If you don't have probable cause to hold my client then I'll be taking him now."

Beckett didn't move. Sammy had given her everything she needed, even if his story checked out they had another suspect now; Barney's 'supposed' biological father. Reilly Kane. Though with their current luck it may just be another red herring.

"Okay then," Anderson Kelly grunted, grabbing O'Doherty's arm roughly, pulling him out of his chair, "Sammy, we're leaving."

O'Doherty had the look of a kicked puppy as he solemnly followed his family lawyer out the door. Castle watched them move toward the elevator intently, only drawing his eyes away when they disappeared from sight.

He looked to his wife, a newfound spark of hope in his eyes, "Reilly Kane?"

"Reilly Kane." Beckett sighed forcefully, giving her husband's arm a quick squeeze as she walked by him.

…

"I mean this case is like a god damn Russian doll." Castle complained. There was a rush of hot air as he opened the oven, pulling a steaming tray of seasoned chicken from it's depths.

"Richard!" Martha scolded, jerking her head in the direction of Felix, who was immersed in his colouring. Too busy roughly dragging a pathetic looking red pencil over the paper to pick up on his father's faux pas.

Kate smiled at Castle's frustration as she collected the cutlery, "Well, I have a good feeling about Kane. I think we're going to find Barney soon."

"You really think so?" Rick carried the meal over to the table, placing it on the grate in the center.

"I hope so. Third time lucky I guess." She straightened a fork delicately as she spoke.

Rick removed his oven gloves, dropping them on the table cloth unceremoniously. "Worked for me." The words rumbled in his chest as he came to stand behind Kate, wrapping his arms firmly around her midsection as she laid up the table. Felix and his mother were facing the other way so he chanced a soft kiss to the smooth, bare skin at the base of her neck.

"Ew." A small voice announced from the counter.

Martha's laugh tinkled, echoing off the walls, at her grandson's unimpressed reaction.

Both husband and wife looked up to meet their son's gaze. They tried to keep the displays of affection PG around Felix, but he was still pretty used to them getting a bit handsy. He'd been perfectly okay with it until about a year ago, when he'd started school, then suddenly he'd begun acting as though it were crass and inappropriate. Making faces as they kissed, though a glittering, playful light shone in his eyes making it clear to them that it was all just a big act. Castle suspected one of the kids in his class had given him the 'kissing is gross' talk.

Kate's hands slipped over Rick's, ready to pry his hands from around her, but Castle only held her closer, harder. Beckett tried not to laugh, abandoning the half laid cutlery as she tried to wriggle from his grasp.

"You know, one day, Dynamo, you're going to be so very thankful for how much your mom and I love each other." Castle told the boy, confident and assured in his words, his hands going further around Kate as he spoke. He began to nuzzle into his wife's shoulder, both of them desperately holding back laughter. Beckett played along, just barely struggling to escape.

"Dad! Mommy!" Felix yelled, his hands going up to cover his eyes, a giggle building.

"Okay Kids, I think that's enough emotional trauma for one evening." Martha joked, clapping her hands to get their attention, "Should we eat?"

"We should." Beckett said, tears in her eyes when she finally broke free Rick's grip. "Felix, can you go fetch Alexis and wash your hands please?"

"Yup," The boy was off his seat and up the stairs like lightning.

"So…" Martha said, sitting down at the table as Rick began to serve up, "are you really that positive about finding this boy or was that all an act for Felix?"

"I…?" Kate was positive, wasn't she? She hoped it was only Martha second guessing her that was sowing a seed of doubt in her mind.

"Mother…" Rick warned, passing the older woman her plate of food. Martha became suddenly very aware of the cornered look in her daughter-in-law's eyes.

"Oh, Katherine, Darling, I wouldn't ask if it weren't for Felix." Martha specified, a rare, wise and solemn edge to her tone, laying a warm hand over Kate's where it rested on the tablecloth. "You and Richard have both been so distracted the past few days, with the mentions of this other little boy constant, it's no wonder the kid has caught on that there's something a little different this time."

Kate was suddenly struck down by guilt, she was usually so careful about referencing cases around Felix, "Martha, I didn't mean to make him uncomfortable-"

The woman held up a hand to silence Kate, "I'm not in any place to tell you how to parent your kid-"

"That's true." Castle muttered, as he neatly sliced up Felix's chicken.

"Not the time, Richard." Martha pursed her lips at her son's comment before continuing, "but I am warning you, Katherine, that you two have brought this story to his attention, knowingly or not, and one day soon he's going to want to know the ending. And, if it's not a happy one you're either going to be breaking that little boy's heart, or lying to him."

Kate's heart clenched. She'd messed up, she'd made all the mistakes she'd promised herself she'd never make with Felix. At six years old everything has a happy ending, the good knight always wins, except reality doesn't work that way. Sometimes the villain got away… and sometimes he didn't, but it hardly mattered, because it was already too late to save the innocent.

She needed this over. She'd needed to find Barney Ryder, and soon, for everyone's sake.