Title: All Our Yesterdays

Summary: AU When Castle's life is threatened, Kate makes the choice to leave everything behind to go after her mother's murderer. Two years later, she returns. But will Castle take her back? Or has too much time passed?

Warning: I like angst. A lot. Fair warning. (I also like happy endings.)

A/N: This is a multi-part alternate universe story, probably 5 or 6 chapters, which I plan to update every couple of days. Flashbacks are in italics. Diverging from current TV story arc sometime mid-season before 47 Seconds, The Limey, Headhunters, etc. Reviews are always appreciated.

Chapter 1: The Return

Two years.

It had been two years since she had been inside this building. Two years since she had made eye contact with the doorman and informed him of whose apartment she was visiting. Of course, after two years, it surprised her that the man even remembered her. But remember her he did – she could tell by how quickly his eyebrows shot up in obvious surprise at her appearance. But the doorman demonstrated his professionalism by merely stating, in halting but firm words, "Good evening, detective. How good to see you again."

"Good evening," Kate responded. She wished she could remember his name, but it would not come to mind. She was already nervous enough. She hadn't anticipated him remembering her, had already composed her explanation for herself and for her sudden appearance.

"Shall I ring Mr. Castle and tell him you are on your way up?" he asked, breaking her concentration. His hand was already reaching towards the phone to make the call. But his question presented an opportunity to delay the inevitable confrontation she was hurtling towards, and she seized on it.

"Um… no, I think I'll just knock," she answered. Better to have this particular reunion upstairs in his loft rather than in the lobby of his building. Less chance of press or paparazzi as well. The last thing she wanted was to cause Castle negative publicity.

As Kate found herself in the elevator moments later, she half regretted the decision. Her stomach flipped somersaults as though she were on a rollercoaster – fear, anticipation, and longing all mixed together in a dizzying frenzy. The pain in her abdomen did not help as it throbbed in time with her heartbeat; the painkillers they had given her at the hospital had worn off hours ago and she could feel the pull of the sutures as she moved.

All too quickly, the elevator arrived at his floor. Kate took a deep breath as she stepped out and turned towards his door, unsure what she would find when it was opened. How would he react to seeing her again after being gone for so long? She knew he would be angry, had already accepted his fury as a given. But would he be happy to see her? Would his rage at her leaving give way to delight at having her back?

She brushed aside such thoughts, already resolved to take the worst of it. While Castle had been uninformed of her whereabouts for the last two years, she had kept tabs on him. Her disappearance had been difficult on him, she knew. He had even tried to find her, spending far too much money in pursuit of her. But she hadn't allowed him to succeed in that endeavor. No matter how much she wanted to see him, the cost was too great.

Having reached his door, Kate tentatively reached a hand up to knock, but she paused, giving herself just a handful of seconds to pull herself together. But she was interrupted before she could complete the task. The door flew open in front of her, the suddenness of it causing her to jump in surprise.

"-more than fashionably late…" She heard Castle's voice a millisecond before she was face-to-face with him, obviously on his way out. A woman in an evening dress trailed a step behind him, almost bumping into him as he stopped dead in his tracks at the sight of Kate Beckett at his threshold.

For a moment, time stopped as they laid eyes on each other.

She could only imagine what reaction showed on her face as she saw him, dressed in a tuxedo for some event or another. He looked the same as she remembered. He had a few more lines around his eyes, perhaps a few more gray hairs, and he had definitely lost some weight. But otherwise, he was exactly the same, the same Rick Castle she remembered, who had starred in her dreams and nightmares for the past two years.

Whatever emotions she betrayed, she was not privy to the same display from him. The sight of her turned his countenance into a stone mask as he stared at her, long and hard. The absolute lack of emotion made Kate wonder if she had changed so much he did not even recognize her… but no, he did. She could see it in his eyes, the way his pupils widened involuntarily, as though attempting to take in the entirety of her in one look.

While his face betrayed nothing, his voice faltered as he uttered a quiet, "Kate."

"Castle," she breathed in response. It came out unconsciously, although she had planned to call him by his first name. But the surname was more comfortable on her tongue, and it was how she usually thought of him in her mind.

"What… what are you doing here?" he stumbled, only his voice showing how shaken he was by her appearance. The woman beside him shifted uncomfortably, clearly recognizing the awkwardness of this scene and her sudden shift in casting from possible leading lady to exit stage left.

For all Kate had imagined seeing him again, for all she had fantasized and rehearsed what she would say, what she would do… it all abandoned her in that instant. She could barely remain standing let alone make an account of herself. But something needed to be said, and she found herself blundering through it. "I found him. He's dead, Castle. That's all I… I mean… I wanted to tell you…"

The woman beside him – presumably Castle's date for the evening – cleared her throat dramatically, as if to remind him of their lateness to whatever function they were on their way to attend.

But Castle seemed not to even hear her, merely repeating, "He's dead?"

Kate nodded, not trusting her voice.

"When… I mean, how long...?" Kate felt better seeing him at the same loss for words, although his clear discomfort at her appearance tore at her insides. She hadn't anticipated finding him with company and on his way out. She did not know the woman he was with although she had seen a couple of pictures of them together in the paper over the last few months. She had suspected them to be just friends, but perhaps the two of them were more? Perhaps the rumors were true and he had finally gotten over her…

She had no right to barge back into his life, she knew. It was a necessary cruelty, but not one she had to thrust on him at such an inconvenient time.

"Look, you're on your way out," Kate acknowledged. "I shouldn't have come by unannounced. I can come back tomorrow, if you want…"

As if to emphasize her point, she took a step back. Giving him a night to get used to seeing her again (and herself a few hours to re-rehearse what to say) would surely be a benefit for them both. Besides, the situation had worked her into such a panic that she had to forcefully suppress a fight or flight response. She had always been good at running way.

"No!" Castle responded almost instantly, springing forward to grasp her hand as though she might dissolve right before his eyes. Recovering at the feel of her fingers in his own, he said firmly, "You're not going anywhere."

The next few minutes were a scattering of sounds and images as he brought her into the loft. Castle's date had been dismissed into the kitchen without even an introduction while he escorted Kate to his office. He only let go of her hand when he had firmly closed the door behind them and stood guard between her and it. Everything in his office looked the same as when she had been here last. Little had changed except perhaps the man standing before her, waiting impatiently for an explanation.

"Castle…" she began, trying to decide where to start.

"Where have you been?" he demanded angrily. "I thought you were dead!"

The possibility had occurred to her, but his vocalization of it forced her eyes to the floor, weighted by guilt. "I've mostly been in the city, searching for him. I went undercover for a while…"

"Kate, you've been gone for two years." It was an accusation, a statement, and a desperate plea for an explanation.

"It was too dangerous to contact you," she said firmly. "If he found out about it, he would have used you against me. He would have tried to kill you, again. But this time, he would have succeeded. Or he could have gone after Alexis, or Martha…" His eyes squeezed shut at her words, and she knew he was picturing the possibilities more vividly than she could describe them. She pressed on. "I couldn't let that happen, Castle. No matter what."

The cost had been great, at least to her. Walking away from him had felt like physically cutting out a necessary piece of herself. The wound had never quite healed, although she had learned to live with the constant ache of their separation. Better for her to feel emotional pain than for him to pay the price in his life's blood. He had already spilled too much for her to ever forgive herself.

Castle spoke in monotone as he noted, "But he's dead now."

No request for details. No demand for the whole story. Just a confirmation of what she had already so inartfully stated in his doorway.

"Yes. He's dead." You and your family are safe, she wanted to say, but couldn't force the words from her lips.

Just a simple goal, but it had been her all-consuming mission for the past two years. Find the man who had killed her mother and keep Castle safe. This objective had driven Kate to leave the NYPD, to turn in her badge and gun in exchange for a life as a vigilante ghost in the city she had grown up in. She had been forced to cut ties to everyone she knew and loved in pursuit of a phantom. And finally, after so much heartache and sacrifice, she could finally report success to the only person who mattered: the man who currently stared at her with features schooled to show nothing but deliberate indifference.

"That's wonderful, Kate. I'm very happy for you." Castle's tone reflected that he was anything but.

For a man who made his living from words, his fell harshly on her ears. They were nothing more than platitudes, equally usable for everyday congratulations on a coworker's job promotion, a cousin's engagement, or the birth of a neighbor's first born. They did not reflect what he was thinking, what he was feeling. Of all the things she had anticipated from this conversation, a brush-off was the least expected.

"I know it's not fair for me to be here, Castle," she tried again. "It's been so long and I'm not expecting anything from you."

"Then why did you come back?" There was the anger again, barely contained behind the cracking façade of his indifference. When she did not answer, he followed up, "You know, I tried to find you."

"I know," Kate confirmed. Staying under the radar of her mother's killer had been difficult, but dodging Castle had proved heart wrenching. While the private investigators he hired would sometimes come close to finding her, she learned quickly how to stay a step ahead. "You must know that I hated having to leave."

"That's just it, Kate - you didn't have to leave. We should have dealt with it, together."

It was a conversation they should have had two years prior, an explanation she thought she had already given when she let him know her decision to disappear.

"He would have killed you," she said with absolute certainty. "He almost succeeded. That's why I left."

Castle couldn't accept it, she could tell. He was already shaking his head, his face flooded with growing rage and betrayal. His lip curled in a furious sneer as he remarked coldly, "So you had to be the martyr, without any regard for what it would do to those of us who care about you." Stopping, he amended himself, "Cared about you."

She tried to respond, stuttering, "Castle, I'm sorry-"

He interrupted her, "You had to go after him all by yourself. Well, sounds like you finally got him. Congratulations, Kate. I'll show you out."

Not having anticipated this turn of events, Kate stared at him for a moment, uncomprehending. She had been gone for so long, and now he was kicking her out? Part of her wanted him to beg him for forgiveness, to tell him the entire story, and perhaps to even declare her feelings for him. But the hurt in his eyes froze the words on her lips. She really had no right to re-enter his life after so many months and expect to still have a place in it.

Accepting her worst case scenario, Kate merely dropped her head as she gave a small nod at his request and left his office. She had never really expected him to welcome her with open arms, not after two years. He had been angry at her self-imposed three month separation the summer after she was shot. She knew that her two year absence would push him too far. She had only hoped, blindly, he would come around.

"I'm sorry I made you late for your evening," she told him quietly as she reached the front door. With a meaningful glance towards the woman waiting in his kitchen, she said, "And I really, truly hope you've found happiness, Castle. That's all I ever wanted."

She did not wait for a response but disappeared out the door, pulling it firmly shut behind her. Slow, measured steps took her to the elevator and the press of a button had her hurtling back towards the ground floor. Giving a sad nod to the doorman, who seemed confused by her reappearance in the lobby so soon, Kate quickly exited onto the night street. The direction didn't matter – she had no where to go, really. She just needed to get plenty of distance before the tears damned up behind her eyes finally broke free.

As the adrenaline from seeing him again wore off, Kate felt the wound in her side throb more painfully. She had a half-forgotten prescription in her pocket for pain medication, but she doubted she would fill it. It was a hard-won injury, one inflicted by her mother's murderer himself. She would bear the pain with pride – the pride of a martyr, as Castle had pointed out - as yet another sacrifice in her now-finished quest.

Two years earlier...

Hospitals held a special terror for Kate. They represented all the horrible possibilities in life – illness, injury, death… Of course, she had not been in this particular hospital when she recovered from her gunshot wound the year before, but hospitals were enough alike that she may as well have been.

Gunshot wound.

GSW.

She flinched at the acronym, knowing exactly how much damage the injury reduced to three letters could wreak on a human being. Then she turned back to look at the patient in the room's sole hospital bed. While the beeping monitor reassured her that the man was still alive, she had to see the steady rise and fall of his chest for herself. Besides, he had been going in and out of consciousness for hours, and she had no desire to miss even the tiniest flash of Castle's beautiful blue eyes.

After all, it may be the last time.

"Richard Castle Shot in Broad Daylight." "Attempted Murderer of Famous Author Still Loose." "First NYPD Muse, then Writer Shot – What Did They Get Too Close To?"

Kate had seen some of the headlines, although she hadn't bothered to read the full stories. She already knew far more than they did anyway, and very little it was. It was a 9mm round, single GSW to the left shoulder. No one had seen anything despite the sidewalk being crowded at 10 AM on a Friday morning. Pandemonium had lost them most of their potential witnesses, although someone had the presence of mind to call an ambulance upon spotting Castle lying on the sidewalk. Someone else had attempted to stop the bleeding, likely saving his life.

Kate hadn't been there. He'd been alone, on his way to join her at the precinct, only a block away from his usual coffee shop. On his way to buy coffee for her, she reminded herself. The thought of coffee made Kate's stomach turn. She hadn't been able to touch the stuff since the call.

One of the first responders had recognized him and known to call her immediately. She'd met the ambulance at the hospital then waited through surgery in the lobby, apprising Alexis and Martha of what she knew when they arrived. The three of them were joined intermittently by others throughout the day – Lanie, Esposito, Ryan, even her dad, Paula and Gina.

Hours had passed since everyone else had been sent home. Kate rationalized remaining in his hospital room as extra protection despite the fact that a uniform was stationed outside. If she were really honest with herself, she needed to be there, to reassure herself that he was okay, that his chest still rose and fell steadily and that the heart monitor still beeped at a constant rate. She needed to hold his hand when his eyelids began fluttering open and he finally awoke enough to ask what had happened. She had to be there to explain - to tell him that his daughter and mother were okay (she had managed to talk Gates into posting another uniform at the loft), that he was okay, that everything was going to be okay. Not that she believed it herself.

Nothing was okay.

Castle was shot in broad daylight in front of a hundred witnesses, and no one had seen anything. She ruled out robbery as a motive when she went through his wallet. He typically carried a substantial amount of cash to pay for cabs, coffee, and take-out, and there were at least nine twenty dollar bills left in the expensive Italian leather billfold. So, not a robbery. The shooting had been too public for a random act of violence.

That left one possibility - he had been targeted. And while Kate did not know the identity of the shooter, she felt absolutely certain of the person behind it. The "Dragon" as McCallister had termed him. The nameless, faceless man who had orchestrated her mother's murder, who had Raglin and McCallister killed and Hal Locklin broken out of police custody, the same man who was responsible for Montgomery's murder and her near assassination... he had finally gone after Castle.

The knowledge of it broke her. Castle had been shot because of her, because of the investigation into her mother's murder. She had struggled during that long summer of lonely recovery to come to grips with the danger she had put those closest to her in. Anyone could have been hurt at Montgomery's funeral, not just Castle as he tackled her to the ground. A stray bullet could have hit Alexis or Martha, Lanie, the boys, or even Montgomery's wife or one of his daughters. The thought of putting them in danger had been part of the reason for her summer of silence, cut off from everyone but her father. How could she justify taking such a risk with someone else's life?

But after three months and no follow-up attempt on her life, she had let her fears go. After reporting to work and working things out with Castle, the doubts seemed silly. If the mysterious man she was trying to find wanted her dead, he could easily do it at any time. While she did not have set hours, she was easy to find, either at the precinct or at home. For someone with a sniper rifle and the experience to use it, she would be a sitting duck.

Taking that consideration into account, Kate wondered why they had gone after Castle. She hadn't gone near the investigation in months, not even so far as to open her mother's murder board. The timing made no sense, and going after Castle? Why him? Why now?

Had she ascribed supernatural features to her mother's killer, she would have thought he chose his time and target to deliberately coincide with one of her most important personal revelations, that she was completely, totally, 100%, head-over-heels, silly-16-year-old giddy in love with Richard Castle. And she was going to tell him. She knew she had to come clean about what she remembered from the shooting, but she also wanted to let him know that she'd decided to break down the wall inside herself. He was already inside, and solving her mother's murder wasn't going to change that. She had already made a reservation for a day next week at a small, expensive restaurant she knew he liked, and she was working up the nerve to ask him out the day he was shot.

The rate of the heart monitor began to gradually increase, and Kate quickly took a seat in the chair beside Castle's bedside, her hand slipping gently into his. A few seconds later, his eyes opened, then shut, then open again. They shut again as he let out a small groan, and she waited to see if he would fall back asleep as he had done half a dozen times since coming out of surgery. But instead, his eyes opened once more and he turned to focus on her.

"Hey," she said, giving his hand a gentle squeeze.

"Kate." His voice was hoarse, but Kate was certain it was the most wonderful sound she had ever heard.

"I'm here," she assured him. She knew how disoriented she had been after waking up in a strange hospital room, in pain, covered in tubes and wires. "You're going to be okay."

He simply stared at her for a long moment, then looked around the room in confusion. Finally, he looked back at her and said without preamble, "I was shot."

She nodded. "The bullet went through your shoulder. You'll need to have physical therapy for that arm, but you were lucky."

"Did he... did he get away?"

She nodded again, feeling for all the world like a child giving a disappointing report to a parent or teacher. "Ryan and Espo are still talking to witnesses, but so far, no one saw anything."

"I never saw the guy. One minute I'm waiting for the walk signal, and the next I'm on the ground. Getting shot really HURTS, by the way. Of course, you knew that..." he rambled, grimacing in obvious pain as he shifted a little in the hospital bed. She saw the moment when he realized what she had already deduced - that the person who shot him was likely tied to the investigation of her mother's killer. And if he was at risk, if he had finally become a target... "What about Alexis? My mother? Are they-"

"They're fine. They were here a few hours ago, but they went home when the doctor kicked everyone out. I have a unit sitting outside the loft, and Esposito said he'd stop by in the morning to bring them up to the hospital to see you."

Castle smirked at her. "The doctor kicked everyone out, huh? What are you still doing here?"

Her eyes softened at his question and her mouth may have even quirked into a small smile. "Sometimes the badge has its privileges, Castle. Besides, there was no way I was leaving."

She expected a joke, maybe even some innuendo, but he simply squeezed her hand, then let it go. "You should go home, Kate. Get some sleep. I'll be fine."

She was so not going to have this argument with him. "You get some sleep," she told him as she stood up. "I'm going to let the nurse know you're awake."

As Kate suspected, by the time she returned from her visit to the nurses' station and a quick trip down to the cafeteria for a cup of tea while they checked in on him (coffee still wasn't appealing), he had already fallen back asleep. Even though it was well past midnight, she sent a short text message to Alexis letting her know that her dad had woken briefly and was resting again. She knew the girl was likely in bed but figured she might sleep better with an update.

The hours spent in the waiting room with Alexis and Martha had been tense – the younger woman mostly ignoring her while Castle's mom gave her pitying looks and absently patted her hand. She felt surprised they didn't scream at her, blame her loudly in front of everyone for what had happened. Castle's shooting was Kate's fault - they had to know that. Even if she hadn't put him at risk with her mother's case, even if this had been an absolutely random act of violence, it was still on her head. She was the cop. Protecting Castle was her responsibility. She should have been there.

If Castle's family agreed with her, they did not speak such reproaches aloud. The three women sat in relative silence until a doctor came in and gave them the news that he would be fine. The bullet had made a clean exit and hadn't hit anything vital. They could likely take him home in a day or two.

A few moments later, she received a reply from Alexis. *Thanks, Detective Beckett. We'll be there first thing in the morning.*

Morning was still hours away, but Kate had no intention of falling asleep. Somewhere out there was a person plotting to end the life of the man sleeping beside her. Her heart dropped into her stomach at the thought of losing him and a wave of nausea swept over her.

She loved him - she knew it in her bones. And his death would destroy her every bit as much as her mother's had. But even worse, it would mean Alexis losing her father, Martha losing her son. The voice of a world-famous author silenced. She could not let that happen. Nothing was worth destroying all their lives.

Sure, Castle had been lucky this time. While a bullet in the shoulder was nothing to sneeze at, he would recover. But what about next time?

Kate could not protect him forever. She doubted she could protect him for one foot outside the hospital if the sniper a mind to take him out. If she could be shot in a cemetery and he could be shot on a crowded street, there was no safety anywhere.

She had dropped the investigation, at Castle's urging. But that clearly had not ended things. He was still out there, the Dragon, and he had gone after Castle. Because of her. This beautiful, loyal, funny man was lying in hospital bed recovering from a gunshot because of her, because she had put him at risk.

Looking over at his sleeping form, Kate knew she had to fix this. She had to take Castle out of the line of fire. He had the resources to leave town and stay out of sight, but she knew he would never agree to do so. Besides, Alexis was about to start college and Martha had her own life. Asking them to live like prisoners in some safe, distant location was out of the question.

Kate had to find the man behind it all. She had to find him and kill him. It was the only way to keep Castle alive and his family protected. And she had to do it alone. She had to stay far away from Castle to keep him from being targeted again. In fact, it would be better for Kate to sever herself entirely from those she held dear if she was going to go up against this phantom.

Mentally planning her strategy well into the night, the darkness outside had just begun to soften into the dark purple hues of morning when Kate found a piece of paper and pulled a pen out of her purse. The letter she wrote was brief but not unsentimental, and she tried to explain her plan without giving away too much information. More importantly, she wanted him to know why, to truly understand the reasons behind her decision.

She had just folded the letter and slipped it into her purse when she heard him stirring again. Morning had dawned while she was writing and daylight peeked from behind the closed blinds. He blinked at her sleepily as she once again reached for his hand.

"Y' look tired," he mumbled, fuzzy from the painkillers. "Told you to go home."

"I will soon," she assured him. "I didn't want to leave you alone."

Her concern must have shown more than she intended, because he looked at her intently.

"I'm okay, Kate." He did not mean the bullet wound, and she could feel tears welling up in her eyes at the thought of him reassuring her.

"Castle, I...I'm..." her voice failed her on the second attempt as she battled the tide of emotions suddenly threatening to wash over her. Fighting back a sob, she managed, "I'm so sorry this happened."

His surprise at her display of emotion momentarily left him speechless, but he quickly recovered. "Everything's going to be okay. You can't blame yourself for this."

"Sure I can," she answered, pushing it all back down, "but let's not talk about it right now. How did you sleep?"

He gave a little shrug but the movement prompted a flash of pain across his face as it disturbed his injured shoulder. "Okay, I guess," he answered. "Weird dreams. Did you get any sleep?"

"A few hours," Kate said, not wanting him to worry.

"Liar."

"Please don't worry about me," she responded, allowing herself to caress his hand very gently. His skin was warm, almost as warm as his eyes as he looked at her fondly.

"Kate-" he began to say. But they were interrupted by a nurse entering to take his vital signs and administer his next dose of pain medication. Giving his hand a quick kiss, Kate stood to leave, forcing herself not to see the surprise on his face as his eyes followed her to the door.

She slipped into the hallway to check on the uniformed officer stationed outside. As he was finishing up his report of a quiet evening, she spotted Alexis, Martha, and Exposito headed in their direction.

"How is he doing?" Alexis asked. The writer's daughter had shown Kate less recrimination than she would have expected, but her eyes still stabbed with the hint of unspoken blame.

"Why don't you go in and ask him yourself," she suggested. Without hesitation, the girl headed into her father's room, and Kate smiled after her.

"And how are you holding up?" she heard Martha ask as the older woman stopped beside her.

"Fine," she responded instantly, a stock response. She was anything but fine. As Martha followed Alexis into the hospital room, she turned to Esposito and asked, "Anything?"

He shook his head. She hadn't expected they would find any evidence, but one could always hope. "How's he doing?" the other detective inquired.

"He'll be okay. Look, can you stay here with them for a while? There are some things I need to take care of..."

Luckily, Esposito earnestly shared her desire to protect Castle and his family. "Sure, sure. No problem. Go do whatever you need to do."

Risking one last look at the door to his hospital room, Kate wondered if she should say goodbye. Would it be too painful, for her and for him? Would it cause her to lose her resolve? Taking a deep breath, she decided against it. After all, she had a lot to do and very little time in which to do it before Castle was discharged in a few days. Besides, she could stop by later and see him after everyone else was gone.

"Was that her?"

Tracy's question was grounded in understanding more than accusation. As a friend from the publishing business, she had known him for a long time, and she knew the story behind the Nikki Heat books, especially his most recent one, Heat Lost.

"Yeah, that was her."

"You two didn't talk for very long."

"Not much to say."

Castle was lying to himself. After two years of separation, he had plenty to say. But he knew Kate had no interest in hearing it. She had clearly blinded herself to the goal of her mission long ago, and nothing could break the sanctity of it. Not even him. Arguing with her would do no good.

Beside him, Tracy let out a noise of exasperation. In some ways, she reminded him a lot of Kate, especially when she called him out on things. Of course, there had never been anything between the two of them. How could there be when he was still in love with a brown-haired former detective? But still, Tracy went to parties with him and helped him keep up appearances as the carefree semi-bachelor to the press.

"That's bullshit," she said bluntly. "You've been searching for that woman for two years, sick to death over her, and she suddenly shows up and 'there's not much to say'? Do you even know where to find her when you come to your senses?"

Castle stared at her for a minute as he let her words sink in. She had a point about not being able to find Kate again. Suddenly, he flashed back to that moment in the hospital when he read her letter and realized she was gone, to the time he let himself into her apartment with a spare key and found it empty and devoid of her presence, to the moment when Gates let him read her letter of resignation from the NYPD. The terror and guilt returned so heavily, he felt the old familiar ache in his shoulder where his scar from the bullet occasionally still itched and pulled.

"You're right," he said to his friend, but his feet were already turned towards the front door. "Um... can you..."

"Let myself out and call Gina to explain why you won't be at the party tonight? I have it covered, Rick."

Without another word, he ran out the door and after Kate Beckett.

The elevator took too long - it was on its way down to the first floor - so he took the stairs, racing as though his life depended on it. By the lobby he was panting and out of breath, but luckily his doorman knew what he was about to be asked.

"She went in that direction," he pointed, then called after the writer as he took off down the street. "Good luck, Mr. Castle!"