a/n: Holy mother of ...is this a COLLIDE update?! Yes, kids, it is. It's been 3 years to the day since the last one, and I figured, ya know. It's time. You won't have to wait 3 years for another one I promise. I'm determined to get this fic finished. I've been on a bit of a roll with that lately, and I always hated leaving this one hanging.

What inspired me to get back to it now? I went back and read some of your wonderful, kind reviews. Knowing how much ppl were enjoying this fic gave me that extra push I needed to get back into it. Help me out and drop a few more of those?

Also, there's mention of an animal death near the end of this first little section here. Proceed with caution if that's a trigger situation for you.

"So here's something interesting," Benson said the next morning. Rollins and Fin both looked up from what they were doing, and she paused between their desks, a folder in her hand. "The DNA retrieved from August Rhodes doesn't match the DNA from Olivia Gable's apartment."

"It's a different doer?" Fin said, face creasing in a frown.

"I'm gonna vote yes, because we did get a DNA hit on one Tyler Mackenzie, age twenty. He's got a couple of solicitation charges, loitering, shoplifting. I seriously doubt he's Olivia's stalker."

"So August's mystery boyfriend was a hooker?" Rollins said. "That…seems unlikely."

"Unless our boy hired this kid. He needed a way into the assistant's apartment. What better than a honeytrap?" Fin said.

"Go pick him up, you two. I think we've got a lot to talk about."

The detectives were back with Tyler Mackenzie in less than an hour, and as they watched him through the observation glass they all agreed on one thing: the kid looked terrified. His nails were chewed down to the quick, his lips were chapped, and every tiny sound spooked him. He didn't look like a junkie; he just looked scared.

"Rollins," Benson said, "I think the two of us should handle this one."

She nodded and accepted the folder Liv offered her. As they entered the room, Benson took the chair opposite Tyler and Rollins laid the crime scene photos across the table. His wide eyes darted from them to the women's faces and back again.

"Can we get you anything, Tyler?" Benson said. "Some water? A coffee?"

"N-no, I'm—what is this? Oh god—that's Auggie." He buried his face in his trembling hands and moaned. "Oh god!"

Benson and Rollins shared a look. "You know this man, Tyler?" Rollins said.

He nodded. "Yeah, of course I do. It's Auggie. He and I were—we were sort of…dating."

"Dating," Benson said. "So he wasn't paying you?"

His head shot up and his eyes roamed the room like a caged animal. "What? No! No, we were—he was—I liked him. He wasn't paying me. He never paid me."

"Okay," said Rollins. "Tell us how you two met."

Tyler scratched his arm. Picked at his cuticles. His leg bounced up and down to some internal metronome set too high. "It was…last week. At a bar. He and some people were there celebrating. He worked at this gallery. This, uh, art gallery?"

At their nods, he continued.

"They had a big opening or something and it went good, so they were having drinks. He bought me one—he thought I was twenty-one, I didn't tell him—anyway, he bought me a drink and we talked. He was—he was smart. Interesting."

"And now he's dead," Benson said, "with your fingerprints and DNA all over his bedroom. That doesn't look good for you, Tyler."

"No, look, no! I didn't know—I had no idea—when I left he was alive!" he cried.

Another glance between the detectives.

"You didn't know what, Tyler?" Rollins said. "He was alive when you left, and you didn't know what?"

He just shook his head, a quick, jerky movement, and stared at his scuffed shoes. "I liked him. I did. He was nice. He treated me nice."

"He didn't know you were a hooker," Benson said, her tone gentle. "He didn't treat you like a john."

Rollins shoved one of the pictures to the front and jabbed it with a finger. "This is what someone did to him, Tyler. Tied him up and strangled him. Left him there alone, and made everything look like you did it. Based on this evidence we don't need a confession. We can arrest you right now!"

He moaned again and banged his forehead against the table. Alarmed, Benson reached for him. "Tyler, stop. Tyler—Detective Rollins, would you go get Tyler a soda?"

She nodded and left, and Benson squeezed his shoulder. "Hey, it's okay. We just need to know your side of the story. Maybe it was a sex game. He wanted you to choke him and things went a little too far?"

He sniffled and wiped the back of his arm across his nose. "No, I swear. He wasn't into anything rough. I had no idea—he didn't tell me!"

"Who didn't tell you, Tyler? August?" She paused and studied his face. "Or someone else? The man who hired you to get close to August, maybe?"

"Oh god, oh Jesus, he'll kill me!"

"We can protect you, Tyler, but we need to know what happened." She fanned out a few of the pictures. "You see these photos? They're pictures of August's boss, Olivia. The man who we think killed August is stalking her."

Tyler bit his lip and reached trembling fingers toward the picture before he jerked his hand back. "Auggie talked about her. His boss? He really liked her. She was gonna help him get into NYU's grad program."

"That's right. She told us the same thing." Benson drew in a breath. "The man who killed August took these photos when he drugged her and tied her up. Now he's kidnapped a police officer, and we're worried he might do the same thing to him. We could really use your help, Tyler."

He shook his head once, hard, but after a moment he started talking. "He said he'd give me a thousand bucks to talk to Auggie in that bar," he said. He rubbed sweating palms on his thighs and looked up at her with pleading eyes. "He said there was another grand in it for me if I got Auggie to take me home. I had no idea he—I mean, yeah, it was a little weird, but it seemed harmless. Like maybe some kinky sex thing they had going, or I dunno—getting back at an ex? I didn't know and I didn't ask. I just needed the money."

He fidgeted a bit. "I liked Auggie. I wasn't expecting that. So when the guy came back later and offered me money to drug him, I said no."

"Drug him?" Benson said. "How?"

"Roofies, I guess. Just put 'em in his drink. Like, me and Auggie'd been seeing each other over the week, just hangin' out. The guy would stop in and give me a few hundred bucks now and then. I felt sorta bad taking it, but I needed the money!"

"It's okay, Tyler," she said. "I understand. Go on."

"Anyway, Friday afternoon he told me to drug August, and he'd give me two grand. I mean, Jesus, another two grand?! But it didn't take a genius to figure out this wasn't a prank or a kinky sex thing. This guy was…he was weird. Creepy. So I told him no."

"What happened then?"

His face contorted with anguish and tears leaked down his cheeks. "He killed my dog! He just—he killed him! He said if I didn't do it, he'd kill me too. Who just kills a dog?! I knew he wasn't fuckin' with me. He'd kill me like you'd swat a fly. He gave me the drugs and told me to give them to Auggie that night, and then leave." He swallowed and scrubbed at his face. "So I did. Then I saw on the news the next day and—I was gonna leave the city, get the fuck out, but—he said he could find me. I don't know how, but I believed him."

"Okay, good. That's good. You were afraid, Tyler. I understand. I'm so sorry about your dog."

He was openly weeping now. "He was such a good dog! Had him since he was a puppy. He kept me company when I had to live on the street. He just killed him!"

"I need your help now, Tyler," she said. "I need you to describe the man who paid you. We need to find him before he hurts August's boss, or my detective."

He scrubbed the tears off his face and wiped his nose with the sleeve of his hoodie. "I can do better than that," he said. "You got my phone? Sometimes I take pictures of johns if they gimme a bad vibe or something. You know, just in case. After he killed Artoo, I snapped a real good one. He didn't know or he probably woulda killed me right there."

Benson's mouth curved in a smile. "That was smart thinking, Tyler. You've helped us out a lot. Stay here, okay? Detective Rollins is going to bring you that soda. Tell her if you need anything else."

He gave a dismal nod, and she left him there wiping at his eyes and sniffling. Fin was in the observation room and he already had the kid's phone.

"That was fast," she said.

He shrugged. "Carisi's a pain, but he's one of our own. Besides, he shaved that greasy-ass mustache and started springin' for normal pizza. Can't let him get his skinny white ass killed now."

"Is it locked?" Rollins said, peering over Fin's shoulder.

"Yep, fingerprint ID."

Rollins took the phone and grabbed the cold soda off the filing cabinet. "I'll be back," she said. "Be ready to run facial rec."

"TARU's already on the way," Fin said.

"Good," Benson said. "Get that ID, and let's find our boy."

"Hey. Hey, asshole, wake up."

Carisi's chair nearly tipped over from the nudge the guy gave him. He'd fallen asleep? Apparently so, because the bag was gone. He drew in several long breaths, more grateful than he could say for some air that didn't smell of dirt and potatoes.

"I'm awake," he said. "Think I could get that piss now?"

The guy grunted. "Only because I don't wanna smell you." He cut the wire ties that held him to the chair and pressed a gun against the small of his back. "Three steps forward there's a bucket in the corner. I'll have this gun on you the whole time, so don't try anything stupid. I'll show you my marksman certificates if you really wanna see 'em."

"That's okay. I believe you." He rose on numb legs and nearly tipped, but at the last minute steadied himself. "Sorry, gimme a sec."

"You got three."

"Okay, okay! Jesus." He shuffled to the corner and his foot hit a plastic bucket. Somehow he managed to pee without making a mess, and when he got back to the chair he was promptly tied to it again. So much for a brilliant escape attempt.

"You wanna know what she's been doing while you've been rotting in this basement?"

From his vicious little tone Carisi could pretty much figure it out. "I don't own her," he said with a shrug. And he didn't. Of course Olivia had been with Barba last night; she felt safe with him, and he would want to look out for her. Sonny was glad she had someone else to turn to while he was indisposed.

And fine they fucked. That wasn't a surprise either. If Barba were the one sitting here and Sonny were the one with her, they probably would've fucked too.

"She likes it rough with him. Real rough. She tell you that?"

His blue eyes narrowed and he tried to twist his head around to get a look at his captor. "How do you know how she likes it? She tell you that?"

There was a brief silence. Then, "She didn't have to. She's a whore; all whores like it dirty."

"Christ, man, get a new tune. This one's real played out. You think you're tellin' me anything about her I don't know? So she likes it rough? So what? They're adults. What they do together ain't anybody's business."

An annoyed sigh. A click, and a projector whirred to life. The wall in front of Carisi was suddenly covered in an enormous image that made him blink. Twice. It was taken from above, and it was Olivia…tied to her bed…on her stomach, with Barba knelt behind her. He had a belt in his hand.

Carisi shifted in his chair.

"Hard to be so open-minded when it's right in your face, huh?"

"She told me about it. I don't give a fuck."

The slide changed, and Carisi immediately flinched.

"What about this one?"

"That's—what he sent her? Your sister? That's her?"

"Yeah, that's her. She was eleven years old when he took this."

Sonny let out a long breath. "You know I catch guys like this scumbag for a living? I stop them from hurtin' little girls like Kaley."

"You're full of shit, Detective Asshole. He went to jail for statutory. That was it. What about molestation? What about child porn? What about this?!" The slide changed again and it was even worse than the other one.

"Boss, I need you to know that this pisses me off about as much as it does you. No kid deserves this. But you know that Olivia is the one who cut off his access to the pageant girls. She did what she did because he hurt another girl, a girl who came to Olivia for help. She threw away her future to protect that girl, and she woulda done the same for Kaley if she'd known."

"Bullshit!" he cried. He charged from the dark and Sonny's chair (with Sonny attached to it) went tumbling. "That's fucking bullshit!"

Sonny's breath left in a pained rush as the dark figure landed on top of him. He latched his hands around Sonny's throat and started to squeeze.

"You don't know shit," he said. "She's leading you around by the cock, and you don't know shit!"

The world was starting to go fuzzy at the edges. Sonny tried to jerk himself away, but between the kidnapper's weight and being tied to a chair, he had nowhere to go. Some far away part of his mind was laughing. What a ridiculous way to die, strangled in a dark basement by a crazy man. Another part was worried because there was no priest, there'd be no last rights. What happened to murder victims when they died? Surely God wouldn't be so cruel…

The pressure was suddenly gone, and he sucked air in through a windpipe that felt like a straw. Why had he stopped? What the fuck was happening?

He thought maybe he heard a commotion, but it was far away. Miles and miles. It didn't help that Sonny was at the bottom of a well, or maybe the ocean. Someplace where the air whistled and the ground was cold. Someplace that made him feel so goddamn heavy. He let his aching head fall to the dirt floor, and gave up his tenuous grip on consciousness.

"He's here!" Rollins called over her shoulder. "Liv, I've got him!" She knelt next to her unconscious partner and felt for a pulse. There had to be one, he couldn't be—shit. Her entire body went limp when she felt the scrambling beat beneath her fingertips.

"He's unconscious. Get the paramedics in here now!"

Benson had joined her by that time. She holstered her weapon and knelt beside Rollins. "Carisi? Sonny, it's Liv. Can you hear me?"

He made a vague sort of noise and his head lolled. There were the beginnings of nasty bruises around his neck, and more on his face.

"It's okay, Sonny," she said. "Help's on the way."

"Liv, take a look at this," Fin said from behind them.

She gave Rollins a look. "Stay with him."

"Not goin' anywhere."

She pushed to her feet and joined him in front of a laptop. "What've you got?"

"Pictures," he said. "Jesus Christ, look at this shit. Kiddy porn."

"The perp's?" she said, frowning at the screen.

"Uhh…well. Some of 'em, I think. Some of these look more like Peterson's MO, from what we saw before. He is one twisted motherfucker." He made a face as he flipped slides, this time to a surveillance shot from Olivia Gable's apartment. "That is not a side of Barba I needed to see."

"Close it," she said. "Don't let anyone else see them. Get them to TARU, but explain the need for discretion."

"You got it." He paused. Lowered his voice. "I thought she was bangin' Carisi."

"I guess she likes to switch things up. Either way, it's none of our business." She gave him a shrewd glare, and he lifted his hands in surrender.

"Message received loud and clear. On my way to TARU now."

When Benson turned away she saw that the paramedics had arrived. Someone had cut Carisi free and they had him stretched out on the floor. One EMT had a stethoscope pressed to his heart, while the other was starting an IV. Carisi already wore an oxygen mask.

"What are they saying?" she asked Rollins.

"Possible concussion. Obviously he was strangled. They're concerned about the lack of oxygen to his brain. Right now he's in and out, so they can't really test his mental capacity."

She and Liv shared a wry glance, but neither commented. Rollins cleared her throat. "Anyway, they're going to get him to the hospital and run some more tests, but he's gonna be fine as far as they can tell."

Benson relaxed just a little. "Thank God. So he's not with it enough to answer any questions?"

"Nope, but hopefully some fluids and a bit of rest and he will be."

"Good. Ride with him to the hospital. I'll stay here with CSU, see if they can find anything that leads us to our perp."

"I can't believe the fucker got away."

Benson sighed and rubbed her forehead with a tired hand. "At least we got here before he hurt Carisi any worse. And we'll catch him. He's running out of places to hide."

"Should someone call Olivia Gable to update her?"

"I'll do it. And I'll get a unit outside her building whether she likes it or not, because now he's on the run, and her place might be his next stop."

"Lieutenant Benson?" It was one of the EMTs. They now had Sonny strapped to a gurney and were about to wheel him out. "He's insisting he talk to you first."

She and Rollins moved closer to the gurney, and Benson rested a hand on Sonny's shoulder. "Hey, Carisi. Welcome back," she said with a soft smile.

"Loo—fuck, throat—his sister."

Her brow scrunched. She glanced at Rollins, but she shook her head in equal confusion. "Whose sister? The perp's?"

Carisi nodded. "The girl in the slides. His sister, Kaley. One o' Peterson's vics." He swallowed around his aching, ravaged throat and licked his lips. "She died. Suicide. Don't know when."

"Okay, okay that's really helpful. Fin took the computer to TARU already. There might be dates and locations."

He grabbed her coat. "Olivia?"

For a second she thought he meant her, but no. She was right in front of him, after all, so why would he need to ask about her? "She's fine. We've got units outside her building and uniforms in the lobby."

"He—was watchin' her."

"We saw that," she said, mildly. "Don't worry. I told Fin to stress the importance of discretion. We've got pics of an underage girl on there, don't forget."

He gave another nod, this one in relief.

"We really need to get him outta here, Lieutenant," the EMT said.

"Go on to the hospital, Carisi. Amanda's going to ride with you to keep you company. I'm calling Olivia right now to let her know you're okay."

"Thanks, Loo," he croaked.

"Yeah, Sonny." She patted his hand. "Let the doctors take care of you. Let us worry about the perp."

Easier said than done, but he managed a lopsided smile for her benefit. The EMTs rolled him away, and Benson took a moment to rub her forehead again. Three detectives for the entire unit. How were they supposed to get anything done with a case this huge, and their every day work piling up? The brass had to give her more bodies, or they might never catch this guy.

Some days she really regretted taking the Lieutenant's exam. Being a boss meant better pay and slightly better hours, but with all the headaches and extra paperwork, she wasn't always sure it was worth it.

pls she loves being the boss.