"I swear, my body clock hates me," Abi groaned, Josh chuckling behind her as she buttoned the bright green coat that was adorning her son.

"It's not that early, Abi," Josh replied, shaking his head, "It's only 6:30am."

"That's plenty early when I don't have to go to work, isn't that right, Cris?" Abi said, turning to the little boy in front of her with a smile, one he returned with equal enthusiasm.

"Momma, we going to park?" Cris asked excitedly, his eyes bright as Josh pulled a beanie onto his head and over his eyes, causing the young boy to giggle.

"Of course we are, silly!" Abi exclaimed, standing as she spoke, the two and a half year old practically exploding with excitement. Amongst Josh's chuckling, Cris began to bound out of his bedroom, plodding all the way over to the door and stopping. He stared expectantly after Abi and Josh, the two of them wandering over laughing to themselves.

"Come on, crazy Cris," Josh added, scooping him up, "We've got a park to get to!"

Abi laughed softly to herself as she watched her son shriek in excitement, Josh opening the door and letting the two and a half year old clamber into the lobby of their Chelsea building. It gave her butterflies in her stomach as she watched her boyfriend and son laugh and play as they made their way to the glass doors. They really were the best two boys she could ask for…

She caught up to Josh who was carrying a giggling Cris on his shoulders, curling herself into the side of his coat, letting the warmth into her fingers.

"So, Cris, what do you want to go on first when we get to the park?" Abi asked, reaching up to grab the young boy's hand, giving it a gentle squeeze.

"Swing!" Cris exclaimed, clapping excitedly, "Swing, Momma!"

Josh gave a quiet chuckle, looking both ways before they crossed the street. Abi gave a glance herself and found her attention caught by the yellow police tape cordoning off a nearby alley.

"What do you suppose is going on over there?" Josh murmured, feeling Abi shrug beside him.

"I don't kn –"

She stopped mid-sentence, a female figure amongst two male ones catching her eye. She was familiar, a little too familiar for Abi's liking. Her hair was a cherry brown, sitting just below her shoulders; she was tall and thin, her heeled boots leaving her at six feet tall. She was wearing jeans and a brown coat, her head down, her face covered by her hair.

She was so familiar…

"Abi!"

Turning at her name, she realized she'd begun to walk toward the crime scene, albeit slowly and only a few steps.

"Oh, sorry," Abi muttered to herself, walking back to Josh, head flicking back over her shoulder a few times. On the third or fourth flick, the woman and the man beside her were looking at her too. She was too far away to discern any notable features, or to get a good look at her face, but Abi was already sure of herself.

She took one more step, but then the woman looked away, almost in an ashamed manner.

"Come on, Abi," Josh urged, tugging her arm in the direction of the park, "it's not her."

"Yeah, yeah, I know," Abi murmured on a sigh, shaking her head at herself for being such a fool.

X X X X X

"Are you sure it's her?" Kate asked, looking from their victim hanging from the fire escape to Castle, who was nodding solemnly. Sighing, she turned to Castle, prepared to speak before a girl in the distance caught her eye, stopping her in her tracks.

"Uh, what are you looking at?" Castle murmured, turning to find his own eyebrows raising.

"Is that –"

"No, it's not," Kate interjected, her eyes still stuck on the figure ahead of her. She had the same brown hair, the same long, slender shape that she'd always had…

But no, that girl was with another man and a little boy, probably her husband and child. There was no way her 22, almost 23 year old sister would be married with a child. No way in hell.

"Are you sure it's –"

"No, Castle," Kate demanded, turning to face him, "it's not."

With that, she turned on her heel, muttered something to one of the uniforms before she headed back to her car.

X X X X X

Kate sat in the interview lounge, Skye Blue sitting opposite her, curled up with a coffee in her hand. She'd asked Castle to sit this one out, knowing she'd get more out of this girl without him. From their last interview, she'd figured out the girl had some serious grudges against her sister, and that was just the beginning of it.

"Skye, if you knew she was in trouble, why didn't you help her –"

"Because she was an ass!" Skye exclaimed, "How was I supposed to get clean when she couldn't even do it?"

"Skye, Haley wasn't using –"

"She was, I saw her with –"

"That was something else," Kate said, referring back to her notes again. Haley hadn't gone to Tony the drug dealer for drugs, but for a gun, the one that was used to kill her.

"Skye, I'm being honest here," Kate continued, "If you knew she was having problems, why wouldn't you help her?"

"I'm guessing you don't have a sister," Skye replied sharply, "because then you would know that they do things that are unforgivable."

"I did have a sister," Kate demanded quietly, "And she was taken from me. She was gone without any thought for what her disappearance would do to me. And that pisses me off; that she would leave without saying goodbye or promising to come back."

Skye's eyes softened, her demeanor changing slightly as the severity of her loss weighed down on her.

"I'm angry at her for leaving me," Kate added, "but ten years on, I've come to realize that it wasn't our fault. Neither of us could have known that after that night we would never see each other again."

Kate watched as Skye's face fell, her eyes dropping to the floor, but rather than remorse, she gave even more anger the next time she spoke, shocking the detective.

"If she weren't such and idiot, then she wouldn't have gotten herself killed," Skye began, her voice raising with each word, "it's her fault that she got killed, and her fault that I don't give a damn. And if you were really telling the truth about your sister, you would still be pissed at her too."

X X X X X

"I'm home, and I – oh, hey Abi."

"Hi Mr. Castle," Abi greeted, flashing the man a grin before she turned back to Alexis, who was intently focused on her laptop.

"So she was found in an alley in Chelsea?" Abi asked, the young redhead beside her nodding vigorously.

"Yeah, you live in Chelsea, right?" Alexis asked, "Did you see the crime scene?"

Abi mused for a moment, thinking back to the scene she'd witnessed this morning and nodding gently.

"You know, I think I did," Abi began, "was she hanging from a fire escape?"

Alexis gave another excited nod, to which Abi raised an eyebrow, chuckling quietly to herself as she shook her head.

"Yeah, I saw it on my way to the park with my boys this morning –"

"Your boys?" Castle asked, a coy grin on his face, "How old is little Cris again?"

"He's two going on twelve," Abi added with a laugh, "At least that's what Nana Barb says."

"Nana Barb?" Alexis asked, "It's not just Nana?"

"No, it's, uh…it's complicated," Abi murmured, eyes dropping, flipping the pen in her hand over and over.

"Well come on, darling, it can't be that complicated," Martha interjected, sipping her wine as all eyes landed on her, Alexis and Castle questioning, Abi's lips pursed as she mused internally.

With a sigh, Abi inadvertently drew the attention back to herself, her green eyes moving up to find Alexis' blue ones staring at her sympathetically.

"I, uh," Abi began, looking down once more before looking back between the Castle family around her, "I was adopted."

"Really?" Alexis exclaimed, Martha cutting in once again after she'd swallowed her mouthful of wine.

"Darling, being adopted is nothing to be ashamed of," she said, laying her hand on Abi's shoulder, "so tell us, how did you come to be adopted."

"Mother!"

Unabashed by Castle's scolding Martha waved him off, turning back to the flustered albeit ongoing Abi. If she was going to tell anyone her story at any time, it may as well be a family she knew and trusted, despite knowing them for only a short time.

"I was, uh, I was adopted when I was twelve, by a family from Rockdale," Abi began quietly, meeting only Alexis' eyes at any one point in time, "but before that I was in an orphanage for a year and a half."

"How did you end up in an orphanage?" Alexis cried, her face contorted into a mix of rage, confusion and pity. Abi let out another sigh, this one shakier than the first, her gaze darting between her audience uncertainly.

"You don't have to tell us, you know –"

"Thank you, Mr. Castle, but I always finish what I start," Abi said, "even if it is just a story."

"It's not just a story," Castle added, "It's your story. It's up to you when, where and how you tell it."

There was silence for a while, a moment or two if Abi were counting, only she was more focused on retelling the hardest part of her story. The part only two other people in the world knew about.

"I came to be in an orphanage because my mother was murdered when I was eleven years old," she continued, amidst stares of both concern, disbelief and, on Castle's part, a little mischief. This only confirmed one of his theories.

"I was with her while she was working, and we were heading to the car to meet my father and sister for dinner," Abi recounted, thinking back to that night in the back of her mind. No matter how hard she tried to push it away, it always hung there; a reminder of what she lost and what she could have stopped. It was a nightmare that returned once too often.

"And all of a sudden, there was a man grabbing her, and she looked like she was screaming, but there was no sound coming out," she said, "And when he stepped back, I saw the knife."

A hand reached out to hers, grasping it the left, her eyes meeting Alexis' when she glanced over. Martha's hand still lay on her shoulder, and had been squeezing it intermittently since she began, while Castle simply looked on in interest and thought.

"I froze, I just…I couldn't move," Abi whispered, "and before I knew it, she was on the ground, bleeding out. She was reaching for me, trying to speak, but she couldn't get the words out. And then, she was gone.

"Before I could do anything about it, the man who killed her grabbed me and started taking me away," she continued, "well, I found my voice, I started screaming, kicking and clawing at the wall to make him stop. Instead, he muttered something about never telling anyone, then whacked me over the head, and the next thing I knew, I was at an orphanage."

Castle watched his mother and daughter silently console the young FBI agent, while he allowed a million theories to run wild in his mind. Her mother was stabbed in an alley. They were on their way to dinner with their family. She clawed at the wall, the only place where her existence was found.

"Once I was adopted, and we moved to Rockland, we would come to the city almost every weekend," Abi added, "Barb and Dale loved the city, and it was the only place I felt at home."

"Did you ever go back?" Alexis asked, "To find your old family?"

Shaking her hung head, Abi didn't allow herself any eye contact.

"Why should I, you know?" she started, "I could have stopped him, could have saved our mother but…I didn't. Why should I go back when I'm the reason we're broken?"

"No, Abi, darling, you couldn't have stopped a fully grown man at eleven years old from committing murder," Martha said, "if you had, you would have both gotten killed."

"Gram's right," Alexis said, "if you were kidnapped, they've probably spent the last ten or more years wondering whether you're okay."

Defiantly, Abi shook her head, "I can't go back. To protect them. It's better if they think I'm gone."

"Now, Abi, if your family is anything like you," Castle began, his hand reaching out to grasp hers, "I know they would want you back."

X X X X X

"Mom, are you okay?" Johanna asked, wandering into her mother's room to find the woman curled up on her bed, a box open and albums adorning the space around her.

Kate's head snapped up, her eyes glistening but she wasn't yet crying, a smile flashed to her daughter before she gestured for her to come over. Climbing up onto the bed, Johanna looked at the picture her mother was staring at intently. It was two girls, one, her mother, probably late teens, the other a younger but almost identical girl Johanna knew to be her aunt.

"Is that Auntie Abigail?" she asked, pointing at the young girl in the photo, whose arms were wrapped around Kate's waist.

Present day Kate nodded gently, sniffing back a tear as she smiled, pulling Johanna closer.

"Yeah, that's her," she affirmed, giving the figure one more caressing with her thumb before placing the photo back in the box in front of her. The box was where she kept everything to do with her sister. Inside were her little sister's first ballet shoes, the birthday card she made for Kate in kindergarten, her charm bracelet that she thought she'd lost…

"You would have liked her, you know," Kate began, turning to Johanna, closing the box gently, "You're a lot like her. Smart, beautiful, outgoing…I was just never like that."

Johanna blinked a few times at her mother, before looking to the box, pulling it closer to her and gently lifting the lid. So far, her mother hadn't stopped her, as she reached in and pulled out a few photographs, skimming through them. One was a beach shot, both girls standing in the water at a much younger age. Another was a Santa photo from 1989, Kate on one knee and Abi on the other. The last one Johanna looked at was a tenth birthday, her mother standing beside a cake, grinning, while a toddler with brown hair and green eyes stood on a chair beside her, arms clamped around Kate's shoulders.

"Where is she now?" Johanna asked, neatly bundling the photos and placing them back in the box, shutting it then looking to her mother.

Kate shook her head, sighing as she did, her arm curling even further around Johanna's frame, "I wish I knew, Jo."

"The case you're working right now is sisters; is that what made you think of her?" the young girl asked innocently, peering up at a solemn Kate with hopeful and supportive eyes.

"Yeah, but we got the guy, Jo, don't worry about it –"

"Are you ever gonna try and find her?" Johanna asked, "Auntie Abigail, I mean."

"It was almost eleven years ago, Jo," Kate reasoned, "She's probably long gone by now."

"But don't you miss her, Mom?" she questioned, watching as her mother's eyes finally met hers for the first time since she stepped into the room.

"More than anything, Jo."

X X X X X

"Ah, come in, Detective Beckett," Castle greeted, stepping aside to allow Kate into the loft. It was warm inside, even warmer than her own apartment where she'd left her father and daughter just half an hour ago.

"Thank you, Castle," she replied, making her way slowly over to the kitchen island, taking a seat on one of the bar stools where she had many times before.

"Where are Martha and Alexis?" Kate asked, looking around the oddly quiet loft for any sign of the famous redheads. Normally, Martha would have jumped at any chance to influence the partnership of Castle and Beckett, but at this moment, she was yet to be seen.

"Mother is still getting ready, and Alexis is with her tutor," Castle explained, "she's coming with us too."

Kate nodded, aware of the glint in his eye, but amiss has to how it related to the tutor of his daughter. Either way, she shrugged it off, puffing out her lips as she watched the man fiddle about the kitchen. His tinkering, however, was a distraction from his pending nerves; what if this girl wasn't her sister? No, the coincidence was too massive for it not to be the one and only Abigail Beckett.

"Can I ask you something?" he began, turning back to the female detective waiting impatiently at his breakfast bar.

"When has my answer ever stopped you from asking a question?" she replied coyly, narrowing her eyes questioningly at him as he chuckled and continued.

"Point taken, but in all seriousness, I want to know," he began, pausing for both dramatic effect and to allow sincerity to fall, "how would you feel about trying to find your sister?"

"Castle –"

"No, just hear me out," he interjected, holding up a hand, leaning forward so his face was no more than a foot from Kate's, "What if someone close to you said they thought they'd found her. What would you do?"

Kate's heart was pounding in her chest, as she mustered all her self-control to not explode out of herself.

"Castle, it took me years to get over the fact that she was gone and we didn't know why," Kate explained, "and now, I'm at peace with her not coming back. I'd appreciate it if you didn't get my hopes up like you did the last time."

There was noise on the stairs, the sound of two young girls laughing, one of them Kate figured to be Alexis, the other her tutor. She snapped her gaze from Castle before he could speak again, not noticing the grin that escaped him as he took a step back. Kate got a hold of herself, leaving all emotion that she didn't need in the back of her mind, as she turned, smiling to greet Alexis as she descended from the top floor.

"Hey Alexis, how –"

The figure beside the youngest Castle stopped her in her tracks. She was tall, thin, brunette, with sparkling hazel eyes, pale skin and her expression was much the same as Kate's.

Abi didn't notice that Alexis had left her side to join her father. She didn't notice that the two Castles were smiling like five year olds at their little mission accomplished. All she saw was the older yet almost identical version of herself, seated at the breakfast bar, jaw practically on the ground.

"Katie?" she whispered, almost ready to pinch herself to see if she wasn't dreaming. In fact, she knew it couldn't be a dream; she'd had many about the day she found her sister again, and never did they feel quite like this. It was almost affirmation that this instance was real, that the woman in front of her was in fact her long lost sister.

"Abi?" Kate murmured, standing slowly as the young girl took another step down.

As if the murmuring of each other's names was a cue, they both ran, tears streaming toward each other, meeting halfway between the kitchen and the staircase. Kate threw her arms Abi's shoulders, squeezing her eyes as tight as she was her sister. Abi let her arms land around Kate's waist, burying her face in her neck, holding on with no intention of letting go.

"I never thought I'd see you again," Abi whispered, feeling Kate slowly release her body, but remained clasping her hands.

"I never thought I'd find you," Kate replied, "where have you been all this time?"

"Everywhere but where I should have been," Abi answered, releasing one hand to wipe away the tears that refused to disappear. Kate took the opportunity to reach into her pocket, pulling out her phone and dialing.

"What are you doing?" Abi asked, Kate holding up a finger as answered the call she'd begun.

"Hey, Dad, it's Kate."

"Katie? What's wrong? Is everything okay?" Jim replied, noting the tears in his daughter's voice.

"No, Dad, everything's…everything is perfect," she replied, sensing the confusion on her father's part, "I have someone who wants to talk to you."

"Well, uh, okay, put them on, Katie."

Slowly, she lowered the cell from her ear and hand it to Abi, both their hands shaking as she took it from her, raising it to her ear.

"Daddy?"

Jim froze. That voice, it was so like Katie's, yet it was different. He knew that voice. It was one he'd yearned to hear for almost eleven years.

"It's Abigail," she continued, sniffing again as she heard what sounded like quiet yet shielded tears on the other line.

"Abigail?"

For the first time since she'd last heard his voice, Abi beamed, the sound of her father on the other line sending butterflies through her stomach. Kate stood opposite her, grinning as well, the Castles just nearby, witnessing the reunion they'd brought about.

"Daddy, I'm home."

X X X X X

I kept it all as one big long chapter because I knew it would take me longer to get the second half out if I split it, then I'd have cranky readers on my hands, and I live only to please you!

Please tell me what you thought, because I had a bajillion different scenarios for this chapter, and this is one I kept coming back to. It was also going to be more case-based, but you know these characters, they practically write themselves.

Anyways, let me know what you thought (:

Kayla x