A/N: Last and longest chapter. It's been fun guys. I love all of you who are reading this. Thank you so much for taking the time to follow/favorite/review.

Disclaimer: At the end of the story, I finally….still do not own Castle. But I will soon own the DVDs :D

Chapter 15

"Hey guys, just stay back a little. We don't want him to know that he's being tailed" Beckett told Esposito and Ryan. She'd left the phone on and Castle was mostly holding it so that she could concentrate.

"'kay boss" came Esposito's answer.

They were trying to hang back as much as possible. It had become a little easier when Smith got into a cab. They had followed him to another street that was seemingly on the other end of the city. He got out of the cab and paid the driver and started walking again. Beckett and Esposito both stopped their cars a little short of where the cab had stopped and parked them there. Once Smith had rounded the corner they quickly got out and put on their vests and had their guns ready. They then ran to make up for the distance between themselves and Smith. When the turned the corner however, he was gone.

He must have entered one of the buildings. This new street was a dead end. They'd have to split up from here. She wordlessly instructed Ryan and Esposito to enter one building, while they entered another. There were four buildings in this street, but the last two would have taken longer for Smith to reach. She saw Ryan and Esposito enter the other building and then cautiously headed into the one she was now facing. Once they were inside, she checked the lobby. There was no one here. No guard, no building occupant, no Smith. She took this time to turn to Castle and handed him a gun. "Castle, for now, you're all the backup that I have. I trust you, you know I do. But please be careful" she said with a small smile. He nodded as he took the gun and then they both headed for the stairs. The elevator was under repair. 'Good, less ground to cover, less chances of escape' Castle thought.

As they made their way up, they stopped on each floor. Some flats had name plates, others did not. They knocked as quietly as they could on the one's that didn't. On two of the floors, from both the un-named flats, they got no response. Since they didn't hear anything suspicious though, they started moving up.

Castle heard Beckett whispering "No, not yet. Any luck on your end?" She had her earpiece on and was talking to either of Rysposito. She shook her head to answer Castle's questioning look.

They heard footsteps coming from above them, on the fourth floor. It could be him she thought; apparently he thought so too as he was the first to move towards the steps. She quickly moved in front of him and whispered with a smile "You still have to stay behind me big guy."

"Right. Sorry" he added with a smile of his own. She went ahead with him following, both their guns drawn.

She knocked on the door behind which the located the source of the noise. "NYPD, open up" she shouted. They heard footsteps headed in the direction of the door. When the door opened, they saw a balding middle-aged man with what Castle presumed was a beer-belly looking clearly freaked out at the two of them aiming their guns at him.

"Jesus! I didn't do nothin'" he said. "I swear!"

"Damn it" Kate cursed as she lowered her weapon. "Never mind, sorry to disturb you. Do you know or have you seen this person around?" she asked him, drawing the photograph of Nathan Smith from her pocket.

The man wiped the sweat from his brow and took the picture with his now sweat covered palm. "Yeah. I've seen this guy. Shady character though if you ask me. Why is a handsome boy like him in street like this?" he ended by coughing.

Beckett looked disgusted, but asked him "He lives in this building?"

"No, lady. He does not."

She glared at him but it didn't seem to affect him. Maybe it would affect him more if he'd just look at her, but he was looking anywhere but at her. 'Sure he didn't do nothin'' Castle thought, but asked, "Uh – so where *does* he live?" getting a little miffed himself.

"He lives in the building opposite this one."

"Okay, thanks" Beckett hurried as she took the photograph back and then turned to run back down the stairs with Castle in tow. As they made their way downstairs, she quickly told Rysposito that Smith would be in their building. Just as they were crossing a street, they heard yelling and gun-shots ringing loudly through the dead silence of the night. They ran the rest of the way and she asked which floor they were on. Ryan answered her and she asked him if they were okay. They got to the right apartment and saw Esposito on the phone calling for an ambulance while Ryan was holding a cuffed, bleeding Daniel Smith to the ground.

As soon as he was done with the call, Esposito approached them. "Jerk tried to attack me with the rod with that symbol thing on it. Ryan shot twice at him, one missed, one hit his shoulder."

After his shoulder was patched up temporarily, Ryan read out the Miranda rights to him while they took him to the hospital for surgery, under the watchful eye of the cops. Esposito told them to make sure that he'd have no chance for escape and that they would come to the hospital themselves soon.

Castle and Beckett were still looking through his apartment. They'd called in CSU by then and they were all looking for evidence. The rod of course was covered in fresh fingerprints since he had tried to attack Esposito with it. It had been wiped clean of blood. Being a scientist, they didn't expect any less. They found a translucent container full of transparent liquid, "probably the anesthetic" Castle suggested. They also found a small box full of needles and syringes, and a bunch of metal instruments which Castle and Beckett didn't recognize. They waited for the major part of the bagging and tagging but didn't stay long enough for the whole sweep through his apartment.

"Come on Castle. It's late. Daniel Smith is in custody, we've got our evidence. I called Gates. She was ticked that I woke her up at this hour but when she realized why she sounded pleasantly happy. I think we should call it a night now. Oh, and you can give me my gun back now." She saw him pout at that last part.

"Darn I thought I could get away with keeping it" he winked. "Let's go home" he said as they started to make their way to the car. "Do we still have to come in early tomorrow?"

She chuckled. "Yes, Castle. At least I do. It's this behind-the-scenes thing that we like to call paperwork" she said, earning herself a smile. "But you can sleep-in if you want. Join me at the precinct later. You did well tonight."

"Oooo! Careful there, detective. All these praises lately. You're going to land up inflating my ego" he smirked.

"I don't think anymore inflation is possible, Rick."

"Ouch! You wound me!" he said with a smirk, but then tailored his expressions. "But seriously, I don't want to sleep in. I'll come in early with you; I want to milk it till I can. I'm going to lose you soon after all" he ended sadly.

She gave him a quizzical look. "What do you mean you're going to lose me?"

"Now that Smith is in jail and you aren't in danger anymore *and* your ankle is all healed, you'll be going home to your own apartment tomorrow. Leaving me all alone" he added a pout. A cute, completely adorable pout.

She'd thought about it. She was going to pack her things tonight but, it made her a little sad too. "You won't be alone for long, Rick. Alexis will be home the day after tomorrow" she said as she parked the car on his street. Someone would be coming to pick it up tomorrow. "And we go back to our routine, you'll still keep seeing me at the precinct every morning." she said as she held his hand.

He intertwined their fingers and said "Yeah. That's the problem, everything will go back to the way it was." He sighed. "It's okay. I'll deal with it" he added a small, unconvincing smile and let go of her hand.

She took back his hand and said "Not everything. Some things will be different."

"Really?" he asked her with a twinkle in his eyes.

"Really. In fact, if we get through paperwork early tomorrow, you want to come over and watch a movie with me?" she asked as they finished putting their shoes and coats away.

He turned around to face her. "What movie do you plan on getting?" he asked as his hands snaked around her waist.

"Hmm. I was thinking about maybe renting 'Inception'" she said while laughing. He couldn't for the life of him understand why that would be funny.

"Oh good! I've been telling you to watch that for ages now! Why is it so funny though?"

She just shrugged and bit her lip before saying, "Maybe I'll tell you, maybe I won't."

He smiled and leaned in to claim the kiss that should have been earlier that night but she moved back in her arms and put her finger on his lips. The look of hurt that flashed through his eyes just melted her heart. He loosened his grip on her, not wanting to force the issue, not having the strength to talk about it. But she didn't take her finger away. She said "Not tonight Rick."

Immediately he perked up, his lips now smiling against her soft finger. "Not tonight! Not tonight doesn't mean never. But can I ask you why?"

"Because if we get started, we won't be able to stop" she said softly.

"And that's a bad thing because?" he smirked, eyes sparkling.

"Because we want to get this – us – right." She replaced her finger with her thumb and gently brushed his it across his lips before taking her hand back.

His smirk turned into the most dazzling smile she'd ever seen him wear. It stretched to his eyes and all the way to her heart. "Yes we do."

She got out of his hold - rather reluctantly – turned to him and said "Good night, Rick." He could only look at her swaying figure heading into the guest room.

"Good night. Until tomorrow, Kate." He called and then headed to his room smiling.

The next morning they ate their breakfast quietly but with loaded and loud stealing glances. They were both sad that she had to leave the loft, but both knew that this day was coming. She did want to get home too, as much fun as it was living with Castle, she needed her space. Once they were done, Castle insisted on carrying her bag and putting it into the trunk of the Crown Vic. Always the gentleman. They even rode in silence, occasionally sipping on coffee to keep it that way.

When they got to the precinct, Gates congratulated them on closing the case, something Castle was yet to completely absorb. Ryan and Esposito were doing their share of the paperwork while Castle and Beckett – by which is meant – Beckett started to do her share. Castle was mostly just staring at her wistfully; she didn't have the heart to reprimand him. It would pass. And they were going to be together for the rest of the day after all – for the rest of their lives, truth be told, she thought happily.

"The guys said that Smith is in recovery from the surgery and that he'll be shifted to lock-up soon. His lawyers will probably try to play the insanity plea. They might actually get away with it but not for MPD" Beckett told him.

"What about Nathan?" Castle asked.

"He's out of police custody. He went to visit his brother at the hospital."

"Family."

"Mhmm" she nodded. "We'll get all the statements by the end of the day and hand over everything to the lawyers."

"We still don't know the exact events thought." He said with a hint of disappointment.

"He isn't talking. I don't think he will either. But we've made pretty accurate guesses so far, mostly you have actually. Have another go at it."

"My guess would be that since he was pretending to be Nathan with Wilkins, he must have lured him to the warehouse promising to show him the very successful results of their on-going experiments. Wilkins ultimately wanted results and until he saw them for himself, I suppose he'd want to keep it all hush-hush. In that case it's believable that he wouldn't have told anyone about the detour he planned from his daily walk."

Kate nodded thoughtfully. "What do you think about those instruments that Lanie said were used on White's eyes, and the anesthetic?"

"About how he got them you mean? I don't know. But it isn't exactly that hard if you try. Black market, maybe?"

"It's possible. He was very resourceful" she said in agreement.

"I'm glad to see this case getting over. Too much drama" he said while shaking his head.

"Says the author of 27 best-sellers" she said with a smirk.

He shrugged. "Truth is stranger than fiction" he said.

"That it is."

"Sooooooo…"

"So what Castle?"

"Are you done yet?" He asked with his brow crinkled and mouth pouting while he put his head in his hands, resting his elbows on the desk.

"No Castle. Have a little patience" she said with amusement filling her every feature.

Ten minutes later she heard him humming "Spider Rick, spider Rick, he's your ruggedly handsome side-kick. Can he swing from a web? No but he – sure can spin it. Watch out….." He didn't finish it because she turned slowly towards him with a glare. She must've been losing her touch he thought because when she turned back he was sure her saw her lips quirk up.

Another ten minutes later, he asked her again.

"CASTLE!" and a real glare shut him up.

"Sheesh. Testy!" he whispered and looked anywhere but at her to avoid her glare.

And so – with the much of the usual – the familiar coffee in the same chair doing the same mundane paperwork while having the same banter she had become so accustomed to, detective Katherine Beckett realized that she wasn't leaving behind the old, but was rather embracing the new.

~The End~