Author's Note: I'd like to thank phnxgrl, southerngirl1, MaineCastle, TORONTOSUN, and Chkgun93 for being the first to review the new story! Chkgun93: sometimes a rollercoaster is the best way to start a story. We're starting this chapter where the last one left off. As always, enjoy!

Chapter 2

Gunshots rang out and Esposito instinctively grabbed his gun and fired into the darkness where he'd seen the muzzle flashes. To his left, Ryan and Beckett did the same as Castle took cover behind them. The shots from down the hallway stopped, so everyone else stopped firing too. Beckett shone her light down the hallway again. Esposito searched everything the narrow beam touched, but he couldn't see anyone.

From nowhere, another shot was fired. Beckett dropped her flashlight with a low grunt and Esposito fired into the darkness again. A yell told him they'd hit something and this time they heard a gun and body hit the ground. Esposito pulled out his flashlight. The beam fell on Beckett laying face-down on the floor.

"Kate!" Castle rushed to her side.

Lanie reached Beckett almost at the same moment. "Let's turn her over."

"We'll check the hall." Esposito and Ryan moved down the hallway with a few uniforms to find out who'd been shooting at them.

Lanie and Castle got Beckett onto her back. "I don't see any blood."

Castle was frantic. "Why isn't she breathing?"

"I don't know." Lanie started CPR as Castle watched, praying she'd be okay.

After a few chest compressions Beckett gasped and coughed, then grimaced as pain registered again. Lanie started examining her friend and found a hole in her shirt. She lifted the shirt and found a bullet imbedded in the Kevlar vest a few inches above Beckett's right hip.

"Girl, you are lucky Castle got you this vest. It just saved your life."

Beckett nodded, still a little winded. "I noticed. What happened?"

"You got shot…"

Beckett interrupted Castle with an amused smile. "I know that part. I'm talking about after I went down."

He helped her sit up. "Ryan and Esposito kept shooting. I think they got them."

Esposito returned. "We did. And we've secured the rest of the old entrance. The gang that lives down here must have reopened the service access tunnel. Explains why no one has reported a lot of tunnel junkies in this area. You okay, Beckett?"

"Yeah, just winded. Who was the shooter?"

"No I.D., just like our other two victims."

Beckett sucked in a breath and grimaced. "I'll head back to the precinct and get started on the board. You guys good here?"

"Yeah, we're good."

Castle helped her stand and stayed close to her side as they retraced their route back to the 96th Street station. Once they were back at the car, Castle took the wheel and drove them back to the precinct. Together, they set up the board, finishing just as the boys came in. The boys filled them in on what little information they'd found after Beckett and Castle had left. A small weapons cache had been found in the "leader's room"; Ballistics was currently taking possession of the guns and would start testing them as soon as they returned to the lab.

"How's Lanie doing with the first victim?"

"They were in the process of getting the train moved so they could find more of him. She'll be down there a while longer." Esposito added a couple notes to the board.

"Lanie helped us figure out what might have happened down there." Ryan pulled up the station's floor plan on his computer. "Alex gets in somehow, makes her way to the stab victim and kills him."

Esposito pointed at the screen. "The guy who got run over hears the gunshots and checks it out. Alex escapes the room, but he catches up to her on the platform. They have a scuffle and he ends up on the tracks as the train comes through."

Ryan sat down. "I'm going to check footage from the bookending stations; see if Alex got to the ghost station from either of them."

"Do we have an I.D. on the stab victim yet?"

"Not yet. Lanie was going to run his prints and DNA when she got him back here."

Meanwhile…

Alex closed the door to the safe house and leaned against it. Her back, knees, hands, and right side were throbbing from being tackled. She shuddered as the image of her assailant being hit by the train swam across her mind's eye, again. Normally the sight of blood and death didn't bother her; she'd been surrounded by it for so long that she'd grown accustomed to the sight. That image though, it wasn't something she'd seen before and there was no way to prepare for it.

"Your handiwork is being admired by the police already. I take it things didn't go as planned?"

Alex sighed and pushed off the door. "One of his goons heard the commotion and tried to stop me. It didn't end well for him."

"I take it he's the one who ended up on the tracks. Did he hurt you?"

She nodded. "He tackled me. I probably have a few new bruises now. At least Hammer is dead. Who's on the case?"

"Take a wild guess."

"Kate."

Sloan nodded. "Today is her first day back too."

Alex shook her head. "This is one hell of a 'welcome back' present."

Later that day…

Beckett lifted up her shirt in the ladies room and examined the developing bruise in the harsh glare of the florescent lights. It was already black and blue rimmed with red and purple. She touched it gently and flinched, sucking in a breath and grimacing as pain flared across her side briefly. Maybe she should follow Castle's advice and take off early to have a doctor take a look.

Karpowski walked in. "Ouch. Looks like a doozy."

Beckett dropped her shirt. "Yeah."

Karpowski looked away awkwardly. "Listen, I want to apologize for the way I treated you a few weeks ago. I was out of line."

Beckett dropped her eyes from the mirror, unable to look Karpowski in the eye. "I…"

"You don't have to say anything. You were dealing with just losing your dad and wanted answers. I shouldn't have attacked you like that."

Beckett nodded, a lump in her throat making it hard to talk. "Do you," she cleared her throat, "do you have anything?"

Karpowski shook her head and sighed. "No. Whoever it was...they've gone underground. We've got nothing new to go off of. I'm sorry." She paused. "Could your victim be my perp? You said Alexandra Stevens would kill the man who did it if I couldn't find him."

Beckett shook her head. "Anytime Alex makes a kill that's to protect me, she leaves a file at the scene that proves the connection. She didn't do that this time."

"She was interrupted. Maybe she didn't have time."

Beckett forced a smile. "Maybe. If a file of proof shows up, I'll let you know." Beckett returned to her desk and sat back in her chair. So many emotions were running through her right now. Grief for her father's death, anger at Karpowski for bringing it up, grateful that she had apologized for her antagonistic behavior, and determination to figure out the latest Shadow Fox mystery. Castle set a mug of coffee in front of her and sat in his chair before speaking.

"Is everything okay?"

"Hm?"

"You're staring into space. Something wrong?"

Beckett took a deep breath and sighed. "I ran into Karpowski a few minutes ago."

"Oh. Should I be worried about you getting arrested for assault?"

Beckett laughed. "No. She apologized for how she treated me in Lanie's office a month ago. I'm not sure if I should be glad she apologized or angry at her for bringing up his death again so close to my return."

"Both. She made the effort to repair what could have turned into a burned bridge, but her timing was poor." He blew on his coffee and took a cautious sip. "Have you thought about returning to Dr. Burke for a bit?"

She nodded. "I start next week."

"Good."

Beckett turned her attention to the board and read a note out loud. "'Guns found at the station match a few cold cases. Linked to an enforcer known as 'The Hammer'. Files being sent up.'"

"Esposito went to sign for them a few minutes ago." Castle hooked a thumb toward Ryan. "MTA footage came in a couple minutes before that. Ryan is starting with 96th Street."

"Found her." Beckett and Castle joined Ryan at his desk. "An hour before the call came in, she arrives on the platform and opens up a paper. It hides most of her face from the camera, but that's her."

"How long is she on the platform?"

Ryan sped up the footage until Alex folded up the paper. "Looks like fifteen minutes. She waited until the platform emptied."

Castle updated the board. "So we know how she arrived. Was 96th her exit too?"

Ryan sped the footage up again, stopping as Alex hopped onto the platform again. "Yep. She's got blood on her too. Gave the people at the station a scare; they cleared out pretty quick."

"Which is why we couldn't interview them." Beckett straightened up and pulled a face as her bruise flared with pain. "See if you can get the footage from the surrounding area. It'd be nice if we can follow her home."

"I'll see what I can do."

"Thanks." She turned as the elevator dinged and Esposito stepped off with a file box. "What'd you find?"

He was followed by three uniforms, also carrying boxes. "Lots of cold cases." He set his box down in the Conference Room and grabbed the first file. "The Hammer. Enforcer for hire, so named because he leaves a hammer behind at the scene. The hammer is always clean, no prints or DNA, but there is a DNA profile on file from the scenes themselves that is believed to be The Hammer."

"Is there an identity besides 'The Hammer'?"

"Nope. Just 'The Hammer.'"

"For once in your life, could you stay on camera?!"

Beckett cracked a real smile for the first time in a few hours. "Ryan must have lost Alex. Again." She returned to the bullpen. "Alex give you the slip again?"

He nodded. "I can follow her south for a few blocks, but then she slips into an alley and she's gone."

"Better luck next time."

"Not likely. She seems to know this city like the back of her hand."

Beckett nodded. "Go help Esposito go through The Hammer files. Our case is connected to a few cold ones."

"You got it."

Beckett's phone rang. "Beckett."

"Hey girl, it's me. I ran the DNA on our three victims and got a few hits."

"Who are they?" She grabbed a pen and a stack of post-its.

"Collision victim's name is Roberto DeSable. Shooter is James Kenway."

"And Alex's victim?"

"He doesn't have a name, but he's a match to an unidentified profile in the database. Apparently, he's known only as The Hammer."

Beckett sighed. "Did you try his prints?"

She could almost feel Lanie's scowl through the phone. "Of course I ran his prints. No hits in IAFIS. Now update your board and get your butt down here so I can run you through my findings."

"Okay, Lanie. See you in ten."

A/N: What do you think of the story so far? I couldn't let Karpowski and Beckett remain at odds for too long, and someone had asked what was going on with Karpowski a few chapters ago, so I hope you guys like Karpowski's attempt to reconcile. Leave a review below and thanks for reading!