A/N: Thanks once more for keeping up with this! :) Epilogue will be up tomorrow!

A/N2: Don't let things mislead you too much... this does have a happy ending.

Chapter Twenty

Maelstrom hovered above Central Park, watching as the people ran from him on the ground below. It didn't feel as good as before, and he couldn't figure out why. It was maddening and frustrating.

In anger, he flew down and started his attack.

His first fly-by threw several people to the ground and knocked over trees and statues. Others cowered before him or ran as he stormed through the park. He figured it was more than enough to catch HeatWave's attention. As he closed in on the castle, he saw her quickly approaching.

Then, when he realized how close she was, Maelstrom found himself buried deep within a trench scored across the park, with his nemesis on top of him.

"How did you-?"

Before he could finish, he was engulfed in flames. He called on his power over the wind and air and pushed her away, out of the trench and into a grove of trees.

But she didn't land, just made a huge circle and returned to him, like some sort of flaming boomarang.

"You just can't stop, can you?" he called, stopping her a few feet away. They pushed against each other, both trying to break through, then, their powers exploded, throwing them in opposite directions.

When he hit the ground, he laid there for a time, waiting on the stars to clear from his vision. When he heard HeatWave approach, he acted as if he were unconscious.

She hesitated for a moment before reaching down to take him by the feet. He kicked her back and flew above as she landed several yards away, knocking her through a boathouse and into the pond.

HeatWave coughed and sputtered as she surfaced. Maelstrom was amazed she was able to keep the flames going in her state, but pushed that down when he shot toward her. She wasn't fighting back in the same way as she had before.

"What's wrong, HeatWave? Have you given up already? Because I just got started!"

She burst from the water, her shoulder slamming into his as she pushed higher into the sky, past the clouds and into the freezing and thinning atmosphere. "I don't give up!" she gasped.

Darkness grasped at the edges of his sight and he tried to swing at her, but missed as they both fell toward the earth. He had been mistaken - she wasn't going to stop until she saved the city from him. He couldn't comprehend the idea, yet, something about this discovery felt oddly familiar.

The lack of oxygen caused him to lose consciousness for a few seconds. He came to find the city reached up for him faster than he would like. He called on the wind and regained his balance, flying over New York and ripped the sides off of several of the buildings as he swept past.

Unfortunately, HeatWave was conscious as well.

Their battle continued throughout Manhattan and almost the entire way to Long Island. Maelstrom was soon exhausted. This had to end soon.

He came at her once more, dodging her fireballs and heat pulses as she also raced toward him. She feinted at the last moment, spun, and her heel clipped him across the jaw.

Maelstrom was knocked back, seeing stars again. HeatWave made another pass, and this time, he grabbed her, pushing her through the air and caught her on a bar as they flew past, successfully knocking her down. She fell hard, taking longer to get up this time.

He had to admit, she was persistent, and a formidable enemy. She had chased and fought him all across the city, and now injured, she continued after him.

Her left arm was at an odd angle as she seemed to grow brighter and brighter until his sight was lost.

Maelstrom slammed onto the ground, but he refused to acknowledge the burning pain across his shoulders and back from HeatWave's attack. He got up slower than he wanted, but it was quick enough. When she came at him again, he managed to grab her by the arm, and with every bit of strength left in him, he flung her into the nearest building.

This time when she hit, it was different, her flames flickering and fading as she fell, unconscious.

He drifted until he was a few yards away, then walked the remaining distance to her. This was it - the moment when he'd find out who exactly this was, who tormented him so.

And he found, as he closed in, it wasn't as satisfying as he thought it would have, knowing he was about to know the true identity of his nemesis.

Grabbing her shoulder, he rolled her now-flameless body over.

"No-" he gasped, and stumbled backwards, falling hard onto his knees. Her face was covered in drying rivulets of blood, but there was no mistaking her. "No... I... I did this..."

Rick scrambled to her side and pulled her into his arms, trying to fight back the tears. He felt for her pulse, finding it weak, but still there.

"Kate - Stay with me Kate." The voice - his voice - was wrong and he ripped the digitizer from his neck. "I'm sorry - so sorry," he said, rocking her and holding her close. "I didn't know it was you."

Her eyes fluttered open and she seemed so calm. "I did," she whispered.

Rick couldn't believe it - how did she figure out his alias? "How? Why didn't you tell me?"

"Last night..." she closed her eyes and struggled to take a breath. "Your mask."

That explained everything, how Kate acted last night. She must have found it while she was in his office. He never gave it a second thought that she might find it.

"I had... to... to stop..." Kate's eyes rolled back into her head. He could hear the sirens quickly approaching and knew there was no way the medics could get her to a hospital fast enough. He blasted into the air and flew as fast as he could - he had to save her.

Rick found the door to the ER and landed in front of it, not bursting through like he wanted. As he carried her inside, the waiting room hushed as most of the people recognized him and kept their distance.

Their fear permeated the room, and for the first time, he didn't want to feel it.

"Please," his voice breaking as he spoke to the nurse at the front desk, "She needs help. Take her back. Now."

She nodded slowly and called another nurse to take Kate back. Rick could feel the eyes on him, and the security officer's guns pointed at his back. Everyone wisely stayed away from him, and he remained quiet and still until they brought a gurney.

He made sure his movements were slow, laying her carefully on the bed, and stroked her hair. "You're safe now," he said, then watched as the nurses carted her past the doors.

He left, leaping into the air the moment he was clear of the building. He knew what he was about to do wouldn't totally clear his record of destruction, but maybe it would make some sort of difference.

It took him a few seconds to return to where their battle began, and he immediately started repairing the damage. He set the statues right, following the path he'd made just an hour or so ago, cleaning up or re-assembling what he could. Rick could feel the fearful and curious eyes on his back everywhere he went, and it fueled his resolve to make this right.

Finally, when the last brick was set back in place and there was nothing more he could do, he found Kate's former partner, Esposito.

The detective had his gun drawn and watched him closely as he approached. As Rick's feet touched the ground, he removed his mask and raised his hands. "Do what you need to do. I won't fight," he promised.

"Richard Castle?" Esposito stayed still for a moment, recognition ringing clear in his eyes. "Mr. Castle, get on your knees and put your hands on your head. You're under arrest for the destruction of several buildings and for murder."

Rick fell to his knees. He didn't feel the cuffs when they pinched the skin on his wrists, didn't hear as the officer recited his Miranda rights.

He leaned in close to his ear, saying, "You know, I deal with murderers everyday, but I should put a bullet through your skull for killing my partner."

"... What?" he asked, not wanting to believe what he just heard.

"Kate Beckett. HeatWave. She's dead."

He didn't want to continue breathing.

After several moments of the detective's burning gaze, Esposito asked, "Why did you take her to the hospital?" He jerked Rick upwards to stand. "You've been trying to kill each other for almost a month. What changed your mind?"

"I found out who she is - who she was - and I couldn't let her die."

Rick felt his chest tighten painfully as the detective pushed him into his squad car. When the door shut, he wondered again how long had Kate known before she decided to sacrifice herself to stop him.

Then, the awful reality crashed down on him, pushing the air from his lungs - everything he'd ever loved was now gone.