A/N: My initial idea for this story was, "What if "Probable Cause" had happened in late S4 before Kate & Castle were together as a couple. In my mind, it takes place after Pandora/Linchpin, but before 47 Seconds. There is a secondary prompt I used for this as well, but I can't tell you without giving too much of the plot away.:) There are 14 chapters & an epilogue.

Enjoy!

One

For Richard Castle, that March day began as nondescript as any other. The chill in the morning air remained too cool to be considered spring, yet the unpleasant frigidity of winter had thankfully moved on. The sun was shining, barely obstructed by a few puffy white clouds, the birds were chirping and he had a text message from Kate Beckett; all signs the day was going to be a good one.

Though it still felt odd to him to classify days beginning with murder as "good" he rationalized it by telling himself it wasn't the gruesome body or life taken too soon that brought a smile to his face; it was her. Chestnut hair accentuated with honey streaks falling in gentle curls around her shoulder. A gentle smile made from naturally pink lips. And that adorable little mole beneath her left eye. Not to mention the way she said, "Hey, Castle." Almost four years, and the sound of his name on her lips still brought chills.

They met in front of a residential building in mid-town shortly after eight a.m. So many of their days began this way: city traffic behind them and blinking red and blue police cruiser lights illuminating their greetings. To others, it probably seemed silly; to him, life would not have been the same without it.

As he passed over her latte, her lips blossomed further and his heart fluttered in his chest, just as it did every morning. Clearing his throat he asked, "So what've we got?"

"Not sure yet." She led the way into the building and toward elevator, nodding to the officer standing guard with the doorman as she passed by. They rode up to the fourth floor with two techs from CSU. Just outside the apartment—4D—Castle held Kate's coffee so she could put on rubber gloves. Their actions, their patterns were so perfected, so well-polished that neither of them needed to speak. They simply acted.

Castle had to admit this part of their routine had to be one of his favorites. The dance of passing cups and gloves back and forth. It was practically choreographed, though neither of them planned anything in advance; they simply anticipated the others movements as they always did. As Castle grew to understand, Kate particularly appreciated this before early morning cases when she wasn't too keen on being chatty.

When they entered the apartment side by side, Castle hung back in the doorway to observe; to take it all in. It was a nice place. Well lit with many feminine touches. Clearly, a woman lived here, and, judging by the lack of any masculine objects in plain view, she probably did so alone. The citrus orange curtains delicately draped the floor-to-ceiling windows, going nicely with the denim toned chair and loveseat set a few feet from them. Those coupled with the green lampshade told Castle that whoever decorated that apartment was not afraid of a little color and he liked that.

Castle took a few steps forward and scanned his eyes for the victim's body, though it was not hard to find; the couching medical examiner in front of the sofa made that fairly obvious. Taking a step around a crime scene tech canvassing for fingerprints, Castle's eyes fell on the victim and instantly every cell in his body froze; he couldn't have moved forward—not even if he wanted to.

Temporarily oblivious to her partner's statuesque state, Kate stepped into the tight seating area of the apartment and spoke directly to the medical examiner. "What've we got, Lanie?"

"Well," Lanie replied, "it's…something."

When her eyes fell on the body, Kate took a half step back to fully interpret Lanie's assessment. It certainly was something.

A woman was placed atop a wooden coffee table in the center of the seating area. She rested on her stomach with her arms and legs pulled back and hogtied behind her. Her entire head was wrapped in what appeared to be green tinted bubble wrap, thus obstructing her face from view.

Kate squatted down and observed the victim from a different angle. The victim was dressed in dark colored clothing, but when Kate crouched she could see slash marks in the side of the clothes across her ribs and possibly over her chest. "Was she tortured?"

"Looks that way," Lanie said. "From the way these marks bled they were done before she died."

"Cause of death?"

The ME shook her head. "Not deep enough. I'll have to examine her back at the lab to be sure, but I'd guess suffocation was the manner of death."

"TOD?"

"Based on liver temp, between midnight and two am."

Kate nodded and stood. In doing so, she realized for the first time that her usual companion was not beside her. Curious, she turned back towards the apartment entrance and found him frozen just behind the couch. Her brow wrinkled.

Castle had been known to keep his distance at a particularly gruesome crime scene, but this one could hardly classify. Odd, yes. Unfortunate, definitely, but it was hardly gory. She doubted he could even see any blood from his angle. "Castle?" she questioned. He started as though her voice had released him from a trance. "You…you okay over there?"

"Wha—yeah. Yeah I'm fine," he told her, forcing a half smile on his face.

Fine? Fine!? He was about ten thousand miles from "fine." But how could he explain his nausea and palpitating heart to her? How could he tell her he'd seen it all before—in his mind's eye.

Blinking rapidly and shaking his head, Castle attempted to get a hold on himself. Surely, this was not what it looked like. He took a step around the couch to get close to the victim, but yet the scene was exactly as it had originally appeared. Dead woman on a coffee table. Bubble wrap around her head. And was that…? Oh god. Not only was she hogtied, but it was with a scarf—a purple scarf, just as he had described. Jesus.

"Yo Beckett," Esposito said as he walked from the kitchen of the apartment into the main sitting area. "We found a purse on the kitchen table. ID says this apartment belongs to Samantha Tanner, age twenty-eight."

"I won't be able to confirm it's her until I take the bubble wrap off back at the lab," Lanie explained.

Kate nodded to her and then turned back to Esposito and his partner, Ryan. "You two start the canvas; Castle and I will look around here." With the boys dismissed, she turned back to her own partner and noticed his complexion had grown a bit pallid. Now genuinely concerned, she stepped closer to him and asked in a softer tone. "Castle? Are you not feeling well?"

"Wha—oh no, I'm fine. Really. I'm going to go look in the bedroom and bathroom," he informed her. To confirm if my nightmares are coming true, he added in his head.

He swallowed hard and took a deep breath as he walked towards the rear of the apartment. Typically, he would have noticed things—little things. Like, her apartment was atypically tidy for their crime scenes. As most victims did not pre-plan their deaths and clean accordingly, more often than not some clutter, dust or crumbs would be found somewhere in the apartment—if not full scale messes. This apartment, however, appeared as though it had been surgically scrubbed. Castle, however, did not notice that. All he noticed as he made his way towards the back of the loft space was how loud his heartbeat sounded as it was pounding through his brain.

Pausing outside the bathroom door, Castle took a moment to gather his courage—and his breakfast. It was going to be fine; it was all going to be fine. This was…this was just some sort of horrifying coincidence, right?

With all the bravery he could muster, he poked his head into the bathroom and searched for the mirror above the sink. It wasn't hard to find; like most Manhattan apartment bathrooms it was hardly large enough to turn around in. Directly in front of the open door was the sink. Above it, hung a mirror. Scrawled on the mirror in red lipstick were the words "DIE PIGGIE DIE." Just as he had written them.

Castle could feel the bile rising in his throat and he shut his eyes, forcing it back down. This wasn't happening; this couldn't be happening.

That scene in Nikki Heat—the one with the dead, hogtied woman—had never been read by anyone, not even his publishers. He'd deleted it just a few days after he wrote it when he decided to go in a different direction with the story. He'd done that millions of times before with other scenes, so why was this one haunting him? Why had this one come back around? Better yet, who had brought it there?

Those were questions Castle couldn't answer and ones he needed to put aside for another time. Now, the most imminent question was what to tell Beckett? The whole truth? Part of it? Or none at all?

Sucking in a deep breath, Castle took a step into the bathroom and examined the mirror closer. The words were really there. The spent lipstick tube dumped into the sink—also, just as he had written. His original intention in the story was to have a partial print from the killer found on the lipstick tube; he could only hope that part of the story would come true as well.

"Beckett!" he called out finally, still uncertain of what he would say to her when she discovered the killer's twisted message. "There's something you should see in the bathroom."

A moment later she appeared in the doorway. He took a step to his right and ended up jammed in between the toilet and the shower, allowing her a clear view of the mirror. Her brow wrinkled as she stepped into the room and examined the message. She stared at it expressionless for a moment before turning to him. "Piggy is spelled wrong?"

"Yeah, I noticed that," he said, his voice a bit gravely. Just like in the book. At the time, he intended that to be a genuine mistake from the killer—the killer, in his mind, was not as well versed in spelling and grammar as the general populous. It remained simply a piece of backstory he gave the killer. At the time he wrote the scene for Heat that bit of story was completely insignificant. Now, the spelling error taunted him just as much as the familiarity of the victim's body.

Hogtied. Purple scarf. Green bubble wrap.

"Uh," he cleared his throat. A fire blazed across his forehead and down the back of his neck. "You know what, Beckett? I don't think I am feeling well. I think…I think I'm going to go get some air."

Her expression fell into one of sympathy and her tone came out with great caring. "Okay, Castle; I hope you feel better. I'll…maybe see you later?"

He forced his lips to turn into a smile. "Sure. Later. I'll check in on the case." With that, he made his way out of the apartment, not even acknowledging Lanie as he walked past her. He needed air; he needed escape. He needed to figure out what the hell was going on.