Kate accidentally steps on the corner of her canvas bag as she rises, and stumbles back into the bench. A steadying hand grasps her forearm. A broad hand, square nails, a firm but gentle grasp. Kate studies that hand, finds she already knows its lines and planes. A younger version of it handed her a mug of hot tea earlier this morning, brushed the hair back from her face and drew her near for a kiss.

She shakes him off, but doesn't look up right away, schooling her features, tamping down the crazy pounding in her chest with a couple deep breaths through the nose. Then she pulls back a little to take in Charles' height, his broad chest and shoulders, the straight nose and line of his jaw. Intense blue eyes, even more so than Castle's, wait patiently for it, some hint of acceptance, but her interrogation room face is firmly set. Until-

"You must be deadly at the poker table, Kate." He turns to leave, and something breaks loose in her.

"What? No! If you're who you say you are, then stay," Kate blurts out in a rush. She grimaces, irritated with herself.

"I think it'll be better if I don't. Easier."

A stronger breeze comes and blows a loose curl over her eyes. Kate brushes it away in frustration. "Easier for whom?" She swipes the envelope up from the seat and holds it up between them. "This can't be a lifetime's worth of answers, not even close."

She's all fiery intensity now, statuesque and authoritative, even in her maternity. A smile flirts at the corners of his mouth, but Charles buries it when her gaze narrows even more. How many times has his son been on the receiving end of this glare? He's seen dozens of pictures, but in person? Fiercely beautiful Kate. Captivating. No wonder Richard is crazy about her.

Charles nods toward the canvas bag, where the butt of her subcompact Glock barely peeks out from behind the book, "I've been in this game a lot longer than you, Kate. Nikki Heat or not, you won't be able to detain me, or persuade me for that matter. And the last thing I want is for my son to find his pregnant wife handcuffed to a park bench in Central Park."

The challenge hasn't entirely faded from her glare. "This game?"

"Martin Danberg knows exactly who I am. He lied to you both that day in the precinct, but he was right to do it."

Real confirmation, more than just her gut reaction. Kate's ire sags a little under the weight of it.

Charles takes the younger woman's silence as an opening, and presses on. "Sophia Turner was an epic disaster for more than you two, believe me. I didn't recruit her, but I was entirely responsible for Richard's introduction to her."

"Thanks for that, really." Kate is all sarcasm now.

"One of my biggest regrets. I'm glad you both survived it."

"Barely." She can taste the foul Hudson River again and swallows down a faint gagging sensation.

"I was overseas at the time she made her play. I'm really sorry."

A whistle, loud, to the left. Kate swings toward it, and sees the jogger from before, watching them and subtly tapping his wrist with two fingers. She huffs in disbelief. "Seriously? This is some kind of op?"

"I wasn't kidding about the knee, I don't move as fast as I used to. At my age, I'm more about the planning than the execution. I keep a couple of guys around I really trust."

Kate eyeballs the agent's jogging attire and makes a disgusted noise at the back of her throat. "Your man there is a Mets fan. How good can he be?"

The laughter that bubbles up out of Charles makes her heart twist in her chest. She has heard it a thousand times. No doubt. None at all.

"It could be worse, Kate. At least it's not a Red Socks jersey."

A rueful shake of her head. "Can't argue that."

"You actually owe that Mets fan a rather unusual debt of gratitude."

"I don't see how, that shirt is almost unforgivable."

"Kate, he's the last person who saw Representative Stephen Winter alive, and...the first one who saw him dead."

Her breath leaves with a whoosh, the strength in her legs with it. The park bench is just behind Kate's knees, and she gropes for it and sits down. She'd put her head between her knees if the swell of belly would allow for it. As it is, she braces her hands against the metal slats of the bench and prays the leaves under her feet will stop spinning soon.

It's been just over two years since a badly injured Cole Maddox told everything he knew to a federal prosecutor in exchange for a new name and a new life. The fallout was instantaneous. Before the FBI could take U.S. Representative Stephen Winter into custody for questioning, Winter disappeared. The disgraced congressman surfaced a week later in a non-extradition country, flush with drug money from a Swiss bank account, unrepentant and untouchable.

Or so he'd thought.

Charles watches Kate's expression turn to granite, the set of her jaw so tight it looks painful. He starts to form a word, but she cuts him off. "How soon did you know?" she grits out. "How long did Winter operate unchecked while the government twiddled its thumbs?"

"No, Kate, not even...we didn't know until the FBI did. You're Richard's..." Charles blows out a frustrated breath. "Kate, I wouldn't have allowed it."

The fog of shock clears a little, and it hits her, the realization. Kate, wide-eyed, speaks in a steadier voice than she thought possible. "He was killed overseas."

"Yes."

"You can't operate domestically."

"The agency is barred by federal law from certain...practices...on U.S. soil."

"You let Winter go."

"We knew where he was every minute of the way, but yes, we needed him off US soil in order to act. Winter sat on sensitive committees, so much domestic and foreign intelligence data. He was an extraordinary liability. You'll never find anyone to admit it on the record, but it was a sanctioned hit."

The scandal had rocked New York and Washington D.C. alike. The congressional hearings lasted five weeks, and in the end, the FBI arrested four of Winter's D.C. employees, twelve more among his New York office and household staff. With their architect in the wind, one by one, the members of Winter's drug empire turned on one another, all the way down to the street-level drug dealers. The final tally was 41 convictions, the confiscation of nearly $30 million in cash and drugs, and a gaping hole in the drug trade in Washington Heights and the city at large.

A week into the hearings, Beckett's phone rang at 3:37 a.m. The U.S. attorney had staggering news. Half a world away, Stephen Winter was discovered by a Moroccan hotel employee, face down by his Jacuzzi tub, a, double-edged tactical knife protruding from his ruined kidney.

The New York Times headline the next morning said it all: "Corrupt Congressman Lives, Dies, by the Sword." The accompanying article detailed the manner of death of Representative Stephen Winter, and drew the obvious parallel to the stabbing deaths of prominent civil rights attorney Johanna Beckett, her colleagues Diane Cavanaugh and Jennifer Stewart, and court house clerk Scott Murray. Together the group had stumbled upon evidence of wrongdoing that Winter knew would eventually tie back to his organization. They had been executed by a contract killer working at Winter's direction, Dick Coonan. Coonan was years later dead by the hand of Beckett's own daughter, NYPD homicide detective Kate Beckett, in a justified shooting. The younger Beckett's tireless investigation into the death of her mother was an ongoing threat to Winter's criminal enterprise. More thugs were dispatched, more lives lost. Detective Beckett narrowly escaped death herself on several occasions, including a sniper's bullet to the heart at the funeral of her own fallen police captain.

The Times concluded that someone in a position to make good on the threat was sending a clear message to any remaining vestiges of Winter's empire: continue at your own peril.

It was over.

Kate cried for two days.

Castle bought a ring.

Kate realizes her eyes are closed, have been for a while. She turns to look at the younger man. He makes no move to approach them, but does take off his sunglasses and allow her to really see him. Clean cut. Military bearing, quietly capable-looking. Six feet tall. Runner's body. Black hair, a little olive in his complexion, part Hispanic maybe. He can't be over thirty years old. He nods, a subtle move, almost like bowing his head out of respect. She'll never know his name. Mets fan. Dragon slayer.

Charles is speaking, she realizes. Kate breaks off her contemplation of the younger agent, and focuses back on her father-in-law.

"Do you know if it's a boy or a girl?"

The baby. He's asking about the baby. Kate relaxes back into the seat back and traces a hand over her stomach.

"Like you don't already know?" She wants it to be a joke, but she's not quite there yet.

Charles smiles for her instead. "You'll have to forgive me, but I have to spend my covert capital in areas more directly tied to our national interests. And it's just a lot easier to ask."

The barest hint of a grin. "We're having a boy."

"Richard must be over the moon."

She nods. "His feet haven't touched the ground yet."

"I'm really happy for him. You're a good woman, Kate. You, Richard, Alexis, Martha, you've made a really nice family together. I want that for him."

"Martha, oh...she..."Kate's thought fizzles, and she shoots Charles a questioning look.

"She's in the letter, Kate. A lot of what I've told you was too sensitive to put in writing, but Martha, she's in the letter."

"You know Rick will never keep this from her."

"I'd never ask him to. Whatever Martha has or hasn't told our son, the truth is she's not ignorant of what became of me. I can't imagine you keeping this a secret within the walls of your own home. I trust all of you to do what's right. But will you please give me a day to talk to her first? Martha doesn't know that I'm here."

"It's not up to me, but I'll tell Rick you asked."

"Thank you, Kate. I really ought to go now."

"Will Castle ever meet you?" Her anxious tone draws a smirk from Charles, and Kate chews her bottom lip in annoyance. The pretense of a calm, dispassionate exterior is well and truly shot. She laughs to herself. "For what it's worth, I'm usually a lot better at being a hard case."

"Don't feel bad, detective. I planned this so I had all the advantages," he assures with no judgment in his tone. "Tell me, is Alexis still on track to graduate early?"

"She's due out in May," Kate confirms, her gaze narrowing. "And for the record, it's a little creepy that you know that."

"I suppose it is. I'll try to be in town for it. If you're all amenable. Read the letter, see what Richard wants. I...I don't know how he's going to feel about this. But in the meantime, if you need anything, you know how to find Martin, and Martin knows how to find me."

"I'll give the letter to him." Kate blows out a breath and shakes her head. "About the other...I...I just don't even know what to say."

Charles reaches for her hand, and when Kate gives it, he brings it to his lips for a kiss. "Just take good care of my little grandson."

Kate nods. "I can do that."

With that, Charles turns and heads toward the jogging path. Mets fan hangs back until there's about fifty yards between them, nods one last time Beckett, and walks away.

Kate can't help it, she shoots a few pictures from the hip with her I-Phone as they depart. Surreal, there's no other word for it. She's drained. And buzzing with tension. She has so much to tell Castle. The letter. She clutches it to her chest and checks the time. Castle is due to call any minute now.

Oh, her sweet husband.

After all this time.

His father.