A/N: This might sound sociopathic, but I really enjoyed writing this scene. I promise I'm not an axe-murderer. And even if I was, I don't know where you live, so it doesn't matter anyways. But I hope you enjoy it.

In reply to anonymous reviews:

Mia66—Erm...sorry. I felt bad about it after watching "Poof! You're Dead," because of all the adorableness in that episode. Not quite bad enough to change it, but I definitely felt bad.

You know who it is—yeah, I do know who it is. I appreciate your...death threats, I suppose? Haha, that's my sister, folks. If you care to say hello, watch out. She bites. xD But thanks, Lizard.

Oh, shoot, I didn't add a disclaimer last chapter! Anyways, for this time around, I don't own Castle, except of course the season 2 DVD in my bedroom at the moment. Haha, I'm not funny, am I?

Beckett sprinted up the stairs, closely followed by her weaponless partner. The frantic clack-clack of her boots echoed off the walls of the tiny stairwell.

"Castle, hurry up!" she snapped, more out of anxiety than spite. He panted behind, trying to keep pace. He knew she must've been tense—she only returned to using his last name when she was particularly alert, which meant usually on cases like these. Their killer was a hired hitman, a man who'd been the killer of the victims in many unsolved cases they'd discovered. Castle knew that it was people like this guy that always reminded her of Dick Coonan. He ran a little faster.

The boys were covering the fire escape and the elevator, and as they entered the floor, slamming open the fourth level door, Beckett nodded to Ryan, who was waiting with gun ready.

"Go get him," he said as they passed, his expression, like Beckett's, especially grim. She clapped him on the shoulder and continued, Castle right on her heels.

They slowed as they neared the door. She stopped right outside of it and looked him straight in the eye, as she had done three times since they'd pulled up below the building. "Castle. Stay here."

And for the third time he looked back and replied, "No."

She held his gaze, seeming worried, before she pounded on the door loudly. "NYPD, OPEN UP!"

There was a loud crash, and they glanced at each other. Castle tentatively reached out to try the doorknob, which by some chance of fate was unlocked. He opened it and they slipped inside the room.

As soon as they'd cleared the door, they heard it shut quietly behind them with a creak and a click as the deadbolt slid into place.

Both of them spun around to see that their suspect had already stepped forward and held a gun pointed straight at Castle. "If you move, he dies," the man said simply. Beckett couldn't help but think about the number of times she'd been in this situation, forced to think quickly or else choose between justice and someone's life. Harrison Tisdale, Dick Coonan, Scott Dunn. She didn't know how many times she could continue to come out on top.

"Don't do this," she told him sharply, holding her own gun still, hovering somewhere near her hip. He'd moved to fast to get it up to shooting level, and he could still move fast. If she so much as shifted her weight he'd shoot, and at this point blank range the gun he was holding would blow straight through Castle's signature custom-made bulletproof vest. "Put the gun down."

"I don't think so, Detective. You can't play the upper hand. If you try to take me, your little writer pet will die, no matter what the Kevlar on his chest says."

She was stuck, she knew, until Ryan could call in backup. He wouldn't come in alone. At least, she prayed he wouldn't. She had to keep the killer talking.

"Why'd you do it?" she asked.

He chuckled. "Don't you know, Detective? You two are the mystery solving team who lives in infamy among us criminals. Surely you'd have figured it out."

"Is that really what they call..." Beckett shut him up with a quick glare, and he finished, "I'll find out later."

"So you're a hitman, trained assassin. But why?" she continued. "You can't have thought about what you wanted to do when you were a kid and come up with, 'I want to kill people for a living.' You're a normal guy, besides your interesting profession choice. I want to know why."

"Why are you a detective then?" he smirked. "Was that always what you wanted to be?"

Castle's eyes flitted back and forth between the triumphant look on his face and the blood rushing to her cheeks. He knew everything about her. How did he know?

It was Scott Dunn all over again, a living nightmare. Everything stood stock still for one long moment, in which a second felt like an eternity and the world seemed to have paused in its rotation. Time slowed to a standstill, as though every ounce of that precious commodity had left the room. Time had run out, for good.

And after that moment of silence, of loss and terror, of hopelessness and of things that would never be, the next moment seemed to pass in an instant to Castle and the man with the gun aimed at his chest. But for Kate Beckett, this moment, this last crucial moment, was the important one. She was the only one to realize, as the door smashed open, how the killer tensed in surprise, his fingers tightening on the trigger. She was the only one to register what was about to happen, where bullet was headed as it moved—for her in slow motion, but for everyone else in fast forward. She dove into the path of the oncoming missile, and it exploded into her side with the force of a bomb, sending searing red hot pain through her body. She crumpled into Castle, thrown back by the power. He shouted in the next moment as he realized exactly what had just happened, a moment to late, as around them shots rang out and the killer dropped, instantly dead. The detectives swarmed around them but he just dropped to the floor, holding her limp body to him.

"Kate! KATE!" he yelled. Her breathing was shallow and her pulse raced. "We've got a detective down!"

He vaguely heard Ryan shouting the same message into his walkie talkie. Her eyes fluttered. She coughed blood and it sounded as though the life left her with every movement. "Did we...did we get him?" she whispered hoarsely.

"He's dead, he's gone for good. Hold on, they're calling for an ambulance. You'll be okay." His frantic voice told otherwise.

She laughed gently, her laughter punctuated by more coughing. "Right. Honestly, you're such an eternal optimist."

"You have to be okay," he choked. "You need to. The world needs you. The victims of these crimes that you solve, they and their families need you. I need you."

"There's...there's nothing you can do. There's nothing anyone can do." Her fingers strayed to the bullet hole on her right side, and they came away scarlet. "I know enough about getting shot to know that."

Her eyelids fluttered again. "NO!" he screamed, pressing his hand on the wound to stop the bleeding. "You're going to be fine!"

"Too late," she said faintly.

"It's not too late!" Tears streamed down his face and he brushed them away angrily, then reached into his coat pocket for a small box. He leaned down to hold onto her. "Merry Christmas. Katherine Beckett, will you marry me?

She laughed again, but it was strained and weak. "I don't see how you'll get the chance."

"Please."

She smiled. "Yes."

He slid the ring onto her finger and then he hugged her tightly. "Don't die," he whispered desperately. "I love you."

"You can't stop it," she replied, barely a breath. "I love you too."

He kissed her quickly, before a gentle voice said, "We have to take her, sir." He allowed the paramedics to lift her onto a stretcher and attach her to an IV and an oxygen mask. Once they were in the ambulance, one man began to perform CPR while another bandaged the wound, allowing Castle to ride with them. He held onto her hand and prayed to whoever was listening.

But no one stopped the flat line that sped across the monitor, accompanied by the continuous whine that allowed him only one coherent thought.

Dead. She's dead.

Another thought wormed its way, equally unwelcome, into his mind. It echoed as the first one did and he wished he could plug his ears to it.

Forever.

A/N: I hoped you liked it! As always, let me know what you thought?