"I'm Agent Sorenson with the FBI, this is Detective Beckett and Mr Castle. We're here to speak with Mr Brooks." Will gestured to them, badge in hand.

The young, dark woman behind the desk gave him a swift nod, "Yes, he's expecting you, please go right through."

Richard Castle was slow to follow the Agent as he strode off in the direction of Mr Brooks' office. Pale wood stretched out underneath the writer as he took in the décor. The offices of Ryder and Brooks were spotless and modern; constructed nearly entirely of glass and steel, even the reception desk was glass topped. Being that it was so early, just striking 7:00 am, not many employees or clients seemed to have arrived yet, and the waiting area was but a plain of leather seating and creaseless newspapers.

"Castle? You coming?" Beckett drew his attention back to the task at hand. He slipped past her in the door frame as she stood gripping the handle, holding it open for him.

"This place is… sleek." He whispered, settling on the adjective after a bit of consideration.

"Mr Brooks." Sorenson said, holding out his hand to the man behind the desk in a sign of goodwill. The man was clear suspect; Mr Brooks had a lot to gain from a dead business partner with no heir to lay claim to their share of Ryder and Brooks. With Simon and Fiona gone and Barney out of the way the firm went to him. It was best to keep him convinced that they were only here to informally interview so he'd keep his guard down.

Edward Brooks stood to accept the handshake. He was everything Castle had expected from a thirty year old, comfortable, private attorney; trimmed brown hair, a clean-shaven appearance, and a navy suit tailored to fit. However, his expression was dark, troubled, it didn't match the rest of him. Either he'd just lost his best friend, or he'd just killed his best friend.

"Agent," Brooks responded gruffly.

"Mr Brooks we need to discuss anything you might remember about Simon and Fiona Ryder's disappearance." Beckett said as she took a seat on the opposite side of the desk to their suspect. Sorenson and Castle followed suit.

"Yes, of course." The attorney settled back in his chair, fingers gripping the arms.

"Do you remember the last time you saw Mr Ryder?" Sorenson launched straight into the questions, flicking open his notebook.

"6 pm the Friday before last. I was heading home for the night, he was in his office. Nothing out of the ordinary." The man wrung his hands, concentrating on the memory.

"You didn't see him Monday?" Castle interjected.

"No, Simon called in a day's holiday for himself and Fiona."

Castle's thoughts wandered, revising the case. A sudden phone call from his wife on the Sunday, missing work on the Monday, and missing altogether on the Tuesday, all somehow resulting in the poor guy lying cold in a pool of blood on the Friday.

Kate moistened her lips, leaning forward, "How did he seem on the Friday?"

"Normal." Brooks shrugged, breathing deeply, "He and Fiona were here at 10:00, as always. Fiona left at 3:00 to pick up Barney. They were both in their offices all day."

"Mr Brooks were you aware that Mr Ryder was planning to sell his half of the company?" There was a colder look in Sorenson's eyes as he asked the question.

Simon Ryder's mother hadn't been lying when she said her son told her everything. They'd manage to follow up her tip off about Simon wanting to sell his half of Ryder and Brooks back to the accountants he'd consulted with… who'd been drawing up a quote of 850 thousand.

Edward Brooks hesitated, "I… Yes. Yes, he told me a few weeks ago."

"And you were 'okay' with that?" Castle probed, "Friends since college, business partners. You were just beginning to move away from criminal law and make a name for yourselves as an established executive firm… and Simon bails on you."

"Yes, I was okay with it." Brooks squirmed a little under their firm, insistent gazes, "I mean I was surprised, even a little hurt I suppose, but Simon seemed insistent... I said I was going to buy him out."

"Except you couldn't, could you?" Beckett tilted her head. She reached into her bag and pulled a folder, opening it she placed it on the desk, sliding it toward the attorney. "You recognise this Mr Brooks?"

"It's a statement." The man said shortly.

"It's a statement from your bank concerning your accounts Mr Brooks." Sorenson specified, pointing to the papers. "You lost a lot of money, care to tell us where it's gone?"

"You like the craps tables?" Castle raised an eyebrow, "Or are you more a fan of the races."

"Castle." Kate hissed under her breath.

Edward Brooks nostrils flared, "My father never believed in health insurance, 6 months ago he tells me he's been diagnosed with Thyroid cancer. You know how much that shit costs? $44,000." Castle slunk back in his seat as the man continued, "I have two kids in private school, one's dyslexic, that's another $26,000 easy. That is where the money has gone."

"I'm sorry for my assumptions," Castle muttered. He was a little ashamed. Maybe he'd gotten so used to interviewing dirt bags he'd begun to assume everyone was one.

Beckett was unimpressed with Rick, she didn't even glance at her husband before continuing, "Mr Brooks I'm sorry I have to ask where you were between 11:30 and 12:15 last Thursday night?"

"Home. In bed."

"Can anyone corroborate that?" Kate asked.

"Yes," Brooks chewed his lip anxiously, "My wife, Ellie. My Secretary can give you her details."

"Thank for your time and your patience, Mr Brooks." Sorenson said sincerely, lifting himself out of his chair.

The man nodded, still a little on edge from Castle's accusations. He straightened his tie anxiously. Just as the party of three began to exit Brooks called out for them to wait.

The attorney stood up, "I heard you didn't find Barney? Is that true?" Brooks voice tremored a little, "Do you think that… maybe he's not…" He trailed off.

"It's an ongoing investigation," Beckett looked to Sorenson to see if she was allowed to carry on, he didn't stop her and so she continued, "but there is evidence to suggest Barney was wanted alive. We're hopeful."

"Just, I know that there was never anything formal, so I don't know who Barney will go to now. I want to do whatever I can to help." Brooks offered.

Beckett shared a dubious look with Castle.

"Won't he just go to his grandmother?" Rick said.

Brooks looked unsurely between the trio, garnering how much they knew from their expressions, "Well… no, Simon never managed to legally adopt Barney so won't he go into care?"

"Adopt? He's not Barney's father?" Sorenson lip parted in shock.

Brooks looked bewildered, "No, well not biologically, when Simon met Fiona Barney was already 6 months old."

…

"How the hell was I not given that information?" Sorenson fumed over his espresso, "This could be a parental kidnapping, but I'm being given no information as to who Barney Ryder's biological father is."

"Espos' running down what he can, we'll know in a couple of hours at the most." Kate said wisely, sipping her latte cautiously.

"Makes you wonder what could be so important they kept it out of the unsealed records." Castle had lots of theories but so far none of them were adding up.

The coffee shop was lightly buzzing with life. A couple of tables away two young women were sat with a little boy, maybe three or four years old, he was fussing over his meal. A moment later one of the women leant over and began to cut up the boy's food into tiny pieces. Seeing the action made her think of Felix, the amount of times she'd leant over to cut up his food. Then she thought about Barney, the little boy who wasn't perhaps quite as parentless as they'd originally thought, but still just as alone in the world.

"Kate?" A warm hand covered hers.

"I'm okay." She answered automatically, sliding her other hand over her husband's.

He was stressed today, she could tell. The lack of leads on Barney's whereabouts and their distance from Felix was beginning to frustrate him more than he would let on. She'd seen it earlier when he'd lashed out at Edward Brooks; it was easy to hate people you didn't know when a child's life was at stake.

Kate phone rung, two short, insistent pings, and her hand shot over to greet it.

"Is that Detective Esposito?" Sorenson perked up, gripping his coffee cup tighter.

With just the few words that made up the text Kate's mind began to race "Yes." She breathed.

'Need warrant for FR Witness Protection file. Give me 5.'

"Fiona and Barney, they were in the federal witness protective relocation program." Kate looked up from her phone to meet Will's wide eyes.

"Looks like we were digging into the background of the wrong spouse." Rick concluded.

…

There was nothing of note at the Ryder's house. Everything was as if the family still occupied it, only the lack of food in the fridge and missing clothes in their closets indicated their absence.

Six hours they'd been searching, documenting, photographing, and working with the local police to canvass the neighbourhood, and nothing, not a single lead. No tales of shadowy strangers lurking in cars after dark. No stories of midnight visits from gangs of tattooed men. Nothing to get Castle's blood pumping at all.

"Brooks' alibi checks out." Sorenson strode up to Castle and Beckett where they were stood deep in discussion by the front door.

"His wife could be lying, covering for him." Castle said half-heartedly, knowing he didn't truly believe that Edward Brooks was a killer anymore. The way Brooks had offered to do what he could for Barney had been entirely sincere and void of guilt as far as Castle could tell.

"Nah," Sorenson sighed, leaning against the porch, "We have footage from a neighbour's security cam confirming him coming home at 9:00, so unless he jumped the back fence and flew to New York he didn't do it."

"Well we know Fiona went into Witness protection when she was pregnant, maybe the father's the person she testified against?" Kate suggested aloud what they were all thinking.

"And maybe he found her." Castle added.

"Maybe," Sorenson agreed, "But we won't know until that warrant comes through."

"How hard can it be to get a witness protection file opened when the witness is dead?" Rick wondered aloud, a couple of uniforms pushing past him to enter the house, "The 'protection' part is kind of bereft at this point."

"It is what it is, Castle." Kate said, leaning into him. The day had been long and dragging, the fatigue was beginning to set it. She missed Felix's warm, tight cuddles, and so she tucked herself into her husband's side; settling for the next best thing.

"So," Sorenson, for once, seemed unperturbed by Kate's obvious display of affection toward Castle, "Why don't we knock off now? While we wait for those records I can buy you guys a drink. I think after eight hours on our feet a quick break is fair."

Castle looked to Kate, she was busy thinking on the proposal, and he wasn't about to accept this particular offer without her consent. Sorenson was her ex after all.

"Yeah, why not. They don't need us here anyway." Beckett gave Castle's arm a squeeze of reassurance. "And I need to sit down." She muttered as she walked down toward the car.

…

"Right," Castle clambered off his stool, losing his footing a little, "I need to go to the little boy's room."

Sorenson watched the man as he walked away with a mixture amusement and confusion playing on his features, "He hasn't had the many… has he?"

The bar hummed around them. It was an intimate 'nook and cranny' kind of place, no more than 15 people were huddled around the tables. One barman, a middle-aged guy in a red muscle shirt and apron, stood behind the bar.

Kate was struggling not to laugh as Rick stumbled through the bathroom door, "No, Castle's just a lightweight."

There was a pause. It was less awkward than Kate might have imagined but still stale air hung between them.

"Kate, I'm glad you're happy." Will couldn't quite bring himself to look in her eyes as she said it.

Beckett smiled sincerely at him, "And, are you?"

Looking up at her his eyes were bright, a smile burgeoning, "I am. Libby's… incredible. We may not have everything, but we're happy."

"You miss her." It was a statement, not an inquiry.

Will moistened his lips, his smiled saddened. "She's a journalist, she works from home mostly so she travels with me, but she's in India at the moment."

"A writer?" Kate bit her lip to stifle a laugh, "That's… yin yang, Castle was right."

"What?" Will eyebrow's knitted in his failure to comprehend.

"Nothing." Kate waved the comment away, grinning.

"I know you miss your son too." Will said, running his finger along the rim of his depleted glass. "Whenever we pass a little boy on the street you… you get this look in your eyes."

"I didn't even realise." Kate's voice was quieter now. Felix would probably be getting ready for bed now. Martha or Alexis would be tucking him in, but it should be her, it should be her and Rick.

'There it is again.' Sorenson thought as he studied her face.

"Felix? Right?" The Agent tilted his head at her.

"Yeah." Kate Beckett pictured him as soon as his name was said. Seeing dark hair and shining green eyes in her mind's eye as clear as if he were stood in front of her.

"Can I ask why 'Felix'? It's a little unusual."

"After Felix Leiter." Kate was almost embarrassed as she said it, but not quite, she still thought it was sweet, "The American spy in James Bond. It was Castle's idea."

There was laughter in Will's voice as he spoke, "Can't say I'm suprised."

"Casino Royale was the book that inspired him to write the Derrick Storm series. It was important to him… and I liked the name." When she'd been pregnant the name Joseph had played on her mind nearly every day, but when Felix had been born it just didn't fit, and she hadn't wanted to do it out of obligation. If Kate had said she wanted it then Rick would have folded without a second thought, but she hadn't, Felix was Felix, and she'd never have any regrets about that.

There was a beat of silence.

"You know there's really no point us staying us Boston any longer." Will said, draining the dregs of his beer. "We've done everything we can here, there's no reason we can't head back to New York tonight."

Kate examined his face closely, he wouldn't look at her but it was like he was reading her mind. Was her pining really that obvious?

"You think?" Beckett's tone was hesitant.

"I think we've established that the perp is most likely someone they went to New York specifically to meet with, the APB we put out on Barney hasn't flagged. It's likely that they're still in New York, and that Barney's still in New York, so that's where we should be."

"Will, I'm a professional, I can handle being separated from my family for more than a few days." Kate didn't want him cutting corners for her, no matter how badly she wanted to go home.

"I know Kate, and I honestly think New York is where we need to be." Sorenson seemed sincere, "Anyway, you're not the only one I'm worried about." The agent glanced at the restroom door out the corner of his eye.

"Castle?" Kate's eyebrow shot up. Will Sorenson was worried about Castle?"

Sorenson chuckled nervously, "I know this case has got to be hard on you two. Look, Kate, Castle gets on my nerves, sure. But there's three things I know for sure about him; he cares about you, he makes you happy, and he helps you close cases quicker than any other cop in the city. Except, right now he's on edge. He's worked up about this, even I can see that. I think you both are. I'm thinking maybe when you're back with Felix you'll be able to focus better, solve this case quicker."

Kate gritted her teeth, "I'm fine Will. You think I can't do my job because Castle's distracted?"

"Jesus, Kate. You're only human." Sorenson's fists were clenched on the table top, "Besides, that's not what I'm saying. I'm saying that we've been through this before, a little six year old boy disappearing in the middle of the night, and it ended badly. I'm saying that I know you're scared of how this is going to end, and I'm trying to tell you that you don't always have to be so strong, everyone else is scared too. You think that with Felix as part of the picture losing this little boy could hurt way worse, I get it. You're wondering what it would be like if it were Felix in his place, about your mom and how you have to prote-"

"You don't get to tell me what I'm feeling, Sorenson." Beckett bit back sharply before he could finish, her walls going up.

"Everything okay?" Beckett and Sorenson were locked in a staring match when Castle returned, sitting back down on his stool.

"Course," Sorenson responded, breaking from Beckett's hard gaze, "What would you say to another round, Castle?"

Rick smiled at Sorenson for the first time since they'd been reacquainted, "I'd say you're very kind but I'm going to have to insist on buying this one."

"How could I say no to that?" Sorenson nodded, "But I'll come with you, I want to see what other bitters they've got."

"Be my guest." Rick gestured for Will to lead the way as he climbed off his stool once again, "You okay, Beckett?" Castle asked his wife softly as Sorenson approached the bar.

"Fine." Beckett murmured, her thoughts still pondering lost little boys… and motherless little girls.

Castle knew that look and decided not to push it, simply following Sorenson in haste without another word.

…

Castle had been jittery ever since Kate had told them they were going home, and now they were at the front door he could barely contain himself.

Rick had never been one for homesickness, but there had been plenty of occasions where he'd found it hard being away from his children.

Kate recalled those first few weeks after Alexis had gone away to College, the girl had stayed nearby but still Castle had been worried, distracted constantly; making breakfast for three only to see Martha descend the steps of the loft alone and remember Alexis' absence.

He'd nearly cancelled the first book tour he went on after Felix had been born, but Kate had convinced him he needed to go. The second he'd fallen back through the door two weeks later, bags dumped without a thought, he'd almost flown to his son's crib. Felix had been so small then, just 5 months, and still sleeping some nights in his parent's room.

The movement caused Kate to stir, waking, still groggy, eyes adjusting to the dark to find a familiar shape bent over their son's sleeping form.

'Hi, Felix,' He whispered, bringing his face down to brush his lips against his baby's delicate brow, "I missed you… I love you, Felix."

She watched for a while as he drew the back of a finger down Felix's round, little stomach. The baby's mouth opened in a round 'O' and closed again.

"Hey?" Kate said, just as quietly, Felix was sleeping soundly and the last thing she wanted was to spend Rick's homecoming trying to lull a grumpy baby back to sleep.

"Hi, I thought you were asleep."

Kate hummed in response, she was tired beyond words. Working full days on top of being a temporarily lone parent was exhausting. She closed her eyes, only meaning to do so for a moment, she found she could hardly bare to open them again.

She heard him shift, quiet steps and the muffled rustle of clothing being removed. A weight dipped the bed as he clambered in beside her, rolling over to curl himself, warm and firm, around her. Not bothering to search in the dark for his pyjamas he'd elected to wear just his underwear. She curled into him, tucking her legs in so her heels were against his bare shins. His chest pressed against her back, she could feel his heart beating, rhythmic and comforting.

He sighed, breath hot at her neck, "I missed you too."

"Home sweet home." Rick opened his arms wide and breathed in the loft, "Is it too late to go say goodnight?"

The space was completely silent but for the hum of various appliances and the occasional sound of vehicles passing down in the street. The street lights were all the stopped the black from taking hold.

Kate pondered the little boy sleeping upstairs, "It's late. If we wake him up now he'll never go back down."

Rick's shoulder's slumped, knowing she was right.

Beckett was just as disappointed at her words as he was, but she was determined to see things in a brighter light. The Ryder case was a dark enough presence in their lives without bringing some different form of darkness home with them. She wouldn't let Sorenson's words be the truth, though she secretly wondered if maybe they already were.

"Just think how happy he'll be to see us when he comes down for breakfast tomorrow." Kate slung her arms around her husband's neck, bright eyes searching his for that spark she knew so well.

It appeared suddenly, dancing amongst the blue, "I'll make s'morelettes." He whispered excitedly.

Kate began a low groan, no doubt planning to derail his breakfast plans with a swift 'No, Castle.', but the Rick drew his arms tight around her, dipping his head to kiss below her ear, and she forgot her disapproval almost immediately.

…

Twists and turns. Castle isn't Castle without them… I hope you guys like where I'm going with this story.