Author's Note: Welcome to the final part in The Shadow Fox Trilogy! This story starts about a month after the last story ended (to avoid confusion, please read the previous two parts). I really hope you guys enjoy the conclusion to The Shadow Fox Trilogy. Enjoy!

Disclaimer: I don't own Castle or the characters, just borrowing them for a bit. This disclaimer will apply to all future chapters.

Chapter 1

Alex clasped her hands behind her back and raised her arms as high as they would go. At the top of the stretch, a sharp pain in the center of her back reminded her that the bruise from Kate's latest bullet had not yet healed completely. She endured the stretch for a moment more and then released it and shook out her arms. She rotated her head around to stretch out her neck and shook out her arms again.

Sloan had caught the grimace. "Back still hurts?"

"Yeah, but only when I move wrong."

"Maybe you should wait until you've healed to go after The Hammer."

Alex laughed. "If I always waited until my latest injury healed, I'd never do anything."

Sloan chuckled too. "I see your point. Do you remember where he's hiding? It hasn't changed."

"His base is in the abandoned 91st Street station. My point of entry is through the 96th Street station. I remember, don't worry."

"I'm not worried."

"Okay then, I'm off. Wish me luck."

"Good luck and be careful."

Alex smirked. "When am I not?"

Alex stood at one end of the 96th Street platform reading the paper. At least, she only looked like she was reading the paper. In reality, she was watching the platform, waiting for the station to clear out enough to jump down to the tracks and make her way to Hammer's hideout. A train was due to arrive any minute, which should do the trick. Right on schedule, the 1 train pulled into the station. Those on the platform shuffled onto the train while a few passengers got off. Two minutes later the train left, leaving the platform empty.

Alex quickly folded up the paper and dropped it in the trashcan behind her before checking that the platform was still clear. She could hear someone coming down the stairs, so she quickly jumped off the platform and ran into the tunnel, heading south. Before long the tunnel grew dark; Alex clicked on a flashlight so she could see where her feet were going. Up ahead, Hammer's ghost station came into view. The platform was derelict, covered in graffiti and dirt from years of disuse.

The best part was the platform was vacant. Hammer didn't expect anyone to wander onto the platform, and he didn't want anyone from a passing train to see one of his men on the platform. Alex jumped up onto the platform and found a spot to hide before the next train rolled by. Once it had passed, Alex headed down the corridor toward the lounge. If Hammer was actively using this station as his base, he would most likely set up shop in there.

Alex hugged the walls, moving quietly as she crept toward the lounge. It was starting to look like Hammer was working with a skeleton crew or had moved. There was no noise down here. She was remembering the last time she'd been in his base of operations; the men in his crew had always been watching some sports game and yelling at the refs when a call went against the team they were rooting for. The silence was unnerving.

Up ahead, a door opened and a wall of noise hit her. "I'll be right back. I gotta hit the head."

She stayed in a crouch as someone still in the room called after the leaving goon. "Hurry up, I need to win my money back."

They've soundproofed a room, that's why I couldn't hear anything. At least she knew Hammer wouldn't be in that room; he hated playing poker. If she remembered correctly, it had something to do with a failed attempt to become a professional poker player. By the looks of things, the lounge had been converted into the hangout room, so Hammer must be in the equipment storage room; it might be the smaller room, but it was private. She stopped in front of the target door and pressed her ear to it.

From the other side came the sounds of an action movie. Probably a Michael Bay film or something like that. Alex carefully opened the door as quietly as possible and slipped inside. Hammer didn't notice her presence as she crept toward him until her shadow fell across the table in front of him. He jumped up, pulling a gun from his waistband, but Alex had anticipated his reaction and managed to stay behind him.

The stab to his kidney was clean, but he didn't go quietly. Hammer managed to fire his gun twice before the shock set in. Alex hurried to stab him twice more, praying that the men in the soundproofed room hadn't heard the shots. For half a moment, she thought that maybe they hadn't. She stabbed Hammer again with a little more precision, severing the inferior vena cava. He'll go quickly now. Alex was about to pull her blade from his back to stab him once more when the door opened with a bang.

In the doorway stood the goon who'd gone to the bathroom earlier. Alex had assumed he'd returned to the game by now; clearly that wasn't the case. For a moment he stood, frozen in place, trying to understand what was going on. Then he saw the blood seeping from Hammer's body and he lunged toward her with a yell, outrage written all over his face. Alex rolled sideways to avoid him and the goon tripped over his boss' body as he slipped in the blood when he tried to change direction and follow her. In the meantime, Alex rushed to her feet and bolted from the room, leaving her knife behind.

Alex ran down the hallway toward the platform. She had no idea what time it was or which train might be passing. The goon coming in had screwed up her kill, making it harder to escape. If she was lucky, he would stay with his boss and try to save his life or he would run for help, giving her time to figure out the trains and escape.

Luck wasn't on her side. Alex heard the goon's footsteps as she reached the platform and he hit her from behind a moment later. Both were knocked off their feet by the collision, rolling out onto the platform in a cloud of dust. Alex tried to get to her feet, but the goon latched onto one of her ankles and pulled her back down. She kicked out blindly and he let go with a curse as her foot connected with something.

Alex jumped up and headed for the edge of the platform again, intending to run across the tracks to the northbound platform. Unfortunately, the goon had also jumped up, grabbing her around the shoulders. Alex dropped her right shoulder down and back slightly, then drove her left elbow into his side as she threw her torso forward. The goon let go as he flipped over her body, landing on the tracks right as the 1 train came through.

The sound of the goon being crushed by the train had Alex gagging as she dropped to the platform to avoid following him onto the tracks. The train screeched to a halt and people inside rushed to the windows to find out what was going on. Alex didn't want to wait around, so she stood back up and dropped onto the tracks behind the train to head back the way she'd come. That didn't go the way I'd planned.

One hour later...

Beckett got out of the car with a sense of déjà vu. A month ago, she had chased Alex from this very area while she'd been trying to lose herself in the crowd. Now she was here again on her first case back since her father's murder. She paused for a moment and took a deep breath, trying to calm her racing heart.

Castle noticed her discomfort. "You okay?"

She shrugged. "Last time I was here, I was chasing Alex."

He nodded in understanding. "I see. I'm sure the boys can handle this if you want to go."

She shot him a look. "I'm not made of glass, you know."

The boys meet them at the bottom of the stairs in the 96th Street station. "Crime scene's a bit of a walk. It's in the 91st Street ghost station. Subway workers flipped the switch in the Lenny Box so the passengers could get out and we can go in safely. The last of the passengers came out a few minutes ago."

"If this is a case where a train hit a tunnel junkie, why were we called in? MTAPD would normally be taking point." Beckett's voice echoed off the tunnel walls as they started their walk.

Ryan held up his phone. "We interviewed some of the passengers as they were brought out. Several of them said they say this girl on the platform."

Beckett took a look at the picture and took a stuttering breath. "Alex. She was here a month ago."

"Maybe you interrupted her a month ago and she decided to lay low for a while." Castle stumbled a little as his toe caught a strut of the tracks.

Esposito shone his light at the tracks. "Careful."

Beckett nodded to Castle's theory. "What do we know about the victim?"

"Nothing so far. There isn't much left of him to identify, at least not that we've found yet." Esposito moved his flashlight around. "We should be getting close."

"We're sure the victim is a man?"

Ryan nodded to Castle's query. "Lanie found a men's shoe with the foot still inside it. I think that's the biggest piece so far."

A light up ahead indicated the platform. Hard at work were the CSU techs and Lanie's crew of M.E. assistants. As the team jumped up onto the platform, they could see Lanie toward the front of the train making notes on her clipboard. Several MTAPD and MTA workers were milling around the platform; a few looked a little green.

"Hey, Lanie, whatcha got?"

"Not much. Cause of death is most likely being run over by a subway train, though I can't rule out being fried by the third rail before the train hit him just yet. Besides that, I got nothing. We'll collect what we can; DNA is our best bet for an I.D. If Alex killed him and then dumped him, we'll probably never know."

"Do we know male of female?"

"A man's shoe with a foot attached says white male, probably 20's to early 30's based on the design and style. That's the best I can do for now."

"Thanks, Lanie."

"Hold your horses, girl, I ain't done yet."

Beckett turned around. "I don't follow."

"Come this way; I've something to show you."

Lanie led them down a hallway into the equipment storage room. "Bloody footprints led me to this room."

"Looks like there was a struggle. Someone slipped in his blood." Beckett looked away as the image of her father's body swam to the front of her mind.

"Alex killed him. This time she left her knife behind." Castle was watching her closely.

"The body under the train interrupts her, they fight, someone slips in the blood," Beckett turned her attention to the footprints on the floor, "most likely the D.B. is the one who slipped. These footprints are too big to be from Alex."

Castle looked around the room as the boys came in. "Looks to me like someone was a long term resident. This place is tricked out."

Esposito jerked a thumb over his shoulder. "The lounge area is tricked out too. I'm thinking this was someone's headquarters."

Beckett was glad for the excuse to leave the room. "Lead the way."

Esposito led the way down the dark hallway toward the lounge. "There's a poker table, giant screen TV, a few gaming systems. I'd say it was a bachelor pad if it wasn't for the location."

Ryan closed the door. "It was soundproofed too."

"Someone was trying to avoid detection." Beckett walked the room, taking in all the items and furniture. "Reminds me of gang hangouts."

Esposito nodded. "That's what I thought. I'm also thinking that Alex's target's room looked like the leader's room."

Beckett moved toward the door. "I'm going to see if Lanie has something new."

She crossed the threshold, intending to return to the remodeled equipment storage room when she heard a sound farther down the hallway. She stopped and looked down the hall, trying to see the source of the sound. The boys had heard the sound too and came out, followed by Castle.

"What was that?"

Beckett shook her head. "Let's find out."

The group moved down the hallway. It got darker, so Beckett pulled out her flashlight and clicked it on. Gunshots rang out from up ahead. Beckett and the boys drew their weapons and fired back. The shots from the shadows stopped, so the team stopped shooting too. Beckett shone her flashlight down the hall again, searching for a body or someone taking cover.

A single shot rang out from down the hall. Pain erupted across Beckett's abdomen as the bullet hit her and she collapsed.

A/N: Starting off with a cliffhanger! Don't forget to leave a comment below; it really helps keep me motivated to write. Thanks!