It was early in the morning and there was very little light as they bent over the body. What happened next shouldn't have happened. It never should have happened. It's just, he just—he said that he'd left something in the van and then he ran across the street to get it. Something, she has no idea what, made her turn her head. The sight was horrific, the SUV striking him and then tearing off, but it's the sound ricocheting in her head that she can't silence. It's like some violent, misbegotten symphony, metal striking bone, glass shattering, tires squealing, his ungodly howl. What are the odds of a crime abutting a crime scene? And more, the victim of the second crime, the man hit by the car, being the medical examiner who was working the first crime scene? Incalculable.

After Sidney Perlmutter was taken away in an ambulance, the new crime scene cordoned off, and the initial chaos controlled, Kate Beckett left her team and went to the hospital. Ten minutes after she arrived Espo called to say that the hit-and-run driver had been arrested, some drunken asshole who had just enough functioning brain cells to tell the officers his name. But that was seven hours ago, and she is still moving restlessly around the same waiting room where her friends and father had paced in agony some years ago, after she had been shot. Probably nothing has changed here since, certainly not the pervasive gloom, the dreary furnishings or the antediluvian magazines. Maybe a few of the uniformly unhealthy things on offer in the vending machine, but that's all. At least she has the comfort, if you can call it that, of knowing that Perlmutter is not in mortal peril, that despite a fractured leg and a dislocated shoulder, he will make a full recovery. But he's also a doctor, and in her experience there are no worse patients than physicians.

Beckett has spoken with Castle, let him know that she will be home late, long after their baby boy has gone to bed. Their son, Eliot, had forged a mystical bond with Perlmutter—whom she had long considered a fine pathologist but an unrepentant curmudgeon—when he was only twelve weeks old. The two of them now are like some bizarre and adorable vaudeville act, a six-month-old infant and a 55-year-old man, mind-reading comedians who require no audience but each other. Because of that relationship, because her heart has softened a little towards Perlmutter, and because she had learned a few months ago that he has no family at all, she has offered to accompany him home and get him settled before the home health aide arrives.

Finally she gets word that Perlmutter and his wheelchair have been secured in the ambulette and are waiting for her at the curb. She goes out, ducks her head in to make sure that he has been told about the drunk driver's arrest, then squeezes his arm before walking to her car. She's following them to his apartment, which is in the least interesting neighborhood in Manhattan. She doesn't know what to expect there, though she has a sketchy notion of a colorless, almost sterile living space. Pulling in behind the ambulette, she looks up at his building, a large, unprepossessing white-brick high-rise that looks exactly like a dozen others that she has passed in the last ten blocks. The driver gets the wheel-bound Perlmutter out of the vehicle and onto the sidewalk. "I'll take over from here," Beckett says. "Thank you so much."

As she pushes the chair into the lobby, she dips her head to her passenger. "How are you feeling, all things considered?"

"Grateful that I am not currently a contestant on 'Dancing with the Stars'."

Definitely not a response she had seen coming, and she laughs as they roll into the elevator. "Maybe next year, Perlmutter. You'll be good as new then. What floor do you live on?"

"Twenty-two. Apartment B. Turn left when we get off; I'm all the way at the end of the hall. I've got my keys," he says, holding them up and rattling them. "I think I can manage the lock from my perch."

She's so stunned when they enter his apartment that she can't hold back a gasp. "Perlmutter, this is beautiful."

"Sorry to have shocked you," he says, the sharp edge back in his voice.

She puts her hand on his uninjured shoulder. "I'm sorry, I didn't mean to sound shocked. I'm not. It's, well. It's." She wishes she could find the vocal equivalent of her feet. "Please, let me start over. It's so simple and elegant, and filled with light. It's serene and private, but welcoming, which is a rare thing to see. You have exquisite taste. I guess I thought that your place would be, I don't know, muted."

"Thank you. That means a great deal."

"Listen, where will you be most comfortable at the moment? Can I get you something from the kitchen?"

"Here by the sofa is fine. And just water, I think. Maybe an apple. They're both in the fridge. Please help yourself to anything. I can't imagine what you've been subsisting on in that godforsaken hospital waiting room."

The kitchen is every bit as startling to her as the living room. It's small, but handsome. There are pots of herbs on the south-facing window, and a table and two chairs. And it is clearly a space for a gourmet cook, a long counter dotted with appliances and gizmos, and three shelves of cook books above. She has to stop to catch her breath. Castle thought there were a lot of layers to the Beckett onion? He should come here.

Two minutes later she's carrying a tray with two bottles of water, some apples and cheese and crackers. "I thought you might like a little protein," she says, nodding at the Stilton as she puts the tray on the coffee table.

"Probably a good idea, a bit of protein. Thank you. It hasn't escaped my notice that you've been running your eyes over the bookcases. Please explore if you like."

"You don't mind if I look around your living room?"

"Not at all. In fact, I wish you would. I know that you're a serious reader; there might be something there that's of interest."

In fact, there are a lot of books that intrigue her, and his range is enormous. She's reaching for a book at the far end, right next to his roll-top desk, when two small framed photos catch her eye. One is of him and Eliot, sharing a private joke; she had taken it on Thanksgiving at the loft and emailed to him. The other is of a woman and a baby, clearly taken some time ago. Beckett is still. And she is suddenly, unaccountably, stricken. Should she say something or leave it alone? She steels herself.

"I'm so happy you like the photo of you and Eliot." With considerable effort, she makes her voice calm, but doesn't dare look at him. "Who's this in the other one?"

The quiet room grows impossibly quieter. Time is frozen. What the hell has she done? She forces herself to turn around. Perlmutter is looking directly at her. She cannot read his expression. It's a mixture of, what? Wistfulness, love, anger? She can't tell.

"I'm so sorry, Sidney, I shouldn't have said anything."

He's still silent. But then he looks down and takes a deep breath. And when he looks back up, he has the ghost of a smile. The kind of smile she used to see on herself.

"It's my wife. My wife, Judith, and our daughter, Abigail. Abby. That was taken outside our little house in Croton-on-Hudson. We had just moved there. A beautiful spot. From our bedroom upstairs we could just see a slice of the river"

She holds his eyes for a long moment before she asks. "What happened, Sidney?"

"They died." It is all he can say at first, and she waits him out. "They died. They died together. Abby would be twenty-five now. But to me she is always eight months old, a happy baby with two bottom teeth and two on top. She hadn't had her first haircut yet. And Judith. Judith is forever thirty. I can't think of them in the now, what they might be or could have been. I can't." He stops again and clears his throat. "It was a train. They had been in the city and had a late lunch with me. My practice was still new and I kept pretty awful hours. Judith took Abby to the zoo in Central Park because she loved the sea lions, and then they caught the train for Croton. I don't know if you remember that accident, you would have been young. The train was going far too fast when it reached the steepest curve on the route, and it derailed. Seven people were killed, including Judith and Abby. My two. My two people."

She feels as if she's strangling. It takes everything for her to choke out, "I'm so sorry, I'm so sorry."

"I worked late that night, and went to get dinner at a coffee shop around the corner from my office before I drove home. I didn't turn the radio on in the car, so I didn't know about the crash. We didn't all have cell phones then as we do now, so no one reached me immediately. But police came to the house, police came to notify me. It was four in the morning by the time I got to the morgue." He stops again.

"I was a pediatrician. But after they died, I couldn't bear it anymore. I couldn't bear to hold a baby who wasn't mine, or hand a baby back to a mother who wasn't Judith. I gave up my practice. I shut myself in for months, but my mind kept turning to the doctor who performed the autopsies on Judith and Abby. He stayed all night with them in the morgue so they wouldn't be alone, can you imagine? So they wouldn't be alone.

"Eventually I did go back to medicine, obviously, but I took some additional training and became a medical examiner. I suppose I became Doctor Death. I sold the house and moved to the city and eventually created this." He sweeps his hand outwards. "An oasis for one. I read, I cook, I listen to music, I work with an orphanage in India and spend my vacation time there every year. Here, I hold everyone away, and I do it by being cantankerous. But that is not, I hope, the real me. It is the façade that I constructed to save myself. It's almost certainly true that the unexamined life is not worth living, but I don't want to spend much time examining mine. The unrealized life? The incomplete life? Those to me are the tragedies."

He levels his gaze at her. She has not been able to stop her tears, but at least she has managed to hold down the sobs. "Do you mind if I ask you something, Kate?"

She wipes the back of her hand beneath her eyes. "Of course not. Anything. Please. I wish that I had known, Sidney. I didn't know. I don't think anyone does."

"You're right. I haven't spoken about my family in decades. I know about your mother's death, and I think that I can comprehend at least some of your loss. What was the thing you most hated afterwards? Besides the absence of your mother, of course. What did you not want to experience?"

She doesn't have to consider the question. Her response is instantaneous. "Pity."

"Exactly, I wanted no pity. I hope you won't mind my saying this, Kate, but I think in some ways we're quite a lot alike. I often think of one of the last lines in Arthur Miller's The Misfits. It's a question. 'How do you find your way back in the dark?' I never really did, though I found my way to something. But you did. You probably aren't aware of it, but I watched you do it. Watched a brilliant woman, so angry and brittle, turn into something else. You found your way back in the dark, and it has filled me with great happiness to see you do it. I wish that I could have done the same. I know that I snipe at Castle, as he does at me. It's a defense mechanism, and it has become habit. In fact, I have come to admire him, and I am forever grateful for what he has done to help you. Don't tell him, but I've read the Nikki Heat series, and I like it very much."

That makes them both laugh, and shoots oxygen into the air.

"May I ask you something, Sidney?"

"Fire away, Captain."

She points to a window on the far side of the room. "You grow orchids. They're beautiful. But aren't they a tremendous amount of work? What made you choose them?"

"Because they last. They last and last. Because they have no scent, so you are aware of them only if you look. Because they flourish with the proper environment, but you have to figure it out. They like to be left alone much of the time. Like me."

He reaches for the water and takes a long drink. "Thank you, Kate. You have Castle and Eliot to get home to. I'll be fine until the aide comes. Truly. I don't want to hold you here."

"What if I want to be here? What if I want to stay for a while, and not leave you alone like the orchids?"

"I'd like that. If you're sure."

"Are you sure?"

"Yes."

"Then I'll stay here until you throw me out."

And so the two of them talk for an hour and a half, new friends who feel oddly like old ones. When the aide arrives, Kate gets up and gives Sidney a gentle hug. "Would it be all right if I brought Eliot over to see you from time to time? You're just about his favorite person on earth."

"I hope you will. He's certainly my favorite person. You could even bring Castle with you, if you like."

"I'll tell him that. I'll call you tomorrow, just to check in, all right?"

"Okay. Thank you."

Kate is at the door when she hears him call her name, and she turns back.

"May I ask you a small favor?"

"Sure," she says, smiling.

"When you get home? Give Eliot a kiss from me. Tell him he's my BFF."

"Will do."

When she reaches her car, she waits several minutes before she drives home. And when she gets there, she goes straight to the nursery, kisses her son and whispers, "That's from your best friend, Perlmutter. I think you're going to help him find his way back in the dark."