I saw something on Tumblr the other day that was set in season 2 of Castle when Beckett's apartment blew up and she stayed at Castle's. She cooks breakfast the next morning and she's wearing a red shirt of Castle's. Here's my take on Castle finding the shirt at Beckett's apartment when they are in a relationship. Set post "Still."

I own nothing of Castle. At all. Mr. Marlowe and company are due all the credit.

Also, this is my first fanfiction, so I'm just trying it out. Just couldn't get this out of my head.

He couldn't sleep.

Every time Richard Castle closed his eyes the image of Beckett standing on that bomb, the seconds ticking by and him powerless to stop it, flashed behind his eyelids.

He rolled onto his side, propping up on one elbow to watch her sleep. They were staying at her place, her need for familiarity and normalcy after today dictating their sleeping arrangements.

Four years ago, when Castle had said Kate Beckett was extraordinary, even he hadn't fully expected how true his words would be.

Kate Beckett was fearless. She chased down murders, fought off a tiger, almost froze to death, had an apartment blow up around her, and lived with her mother's murder every day. Yet…"even on the worst day, there's a possibility for joy," Castle could hear her saying. And the joy was them here, together, happy.

Castle tentatively ran his hand up and down her back, marveling as he frequently did about them being here. A year ago, when Beckett had shown up at his door claiming she "just wanted him," Castle had just been thrilled to have his love returned. Even he hadn't expected Kate to immerse herself so fully into their relationship. Yes, he still had to wrestle back her demons and continued to scale the walls that still crept up, but each day he found himself tearing more bricks down than she was putting up.

Now though, Kate's walls were the furthest thing from Castle's mind. As he lay beside her, the steady rise and fall of her back as she breathed calmed him. The warmness of her skin, still flushed from their lovemaking, was pressed against him-reminding him that they were together, alive. Her honey colored was pulled into a messy bun. Castle could see her eyes darting beneath her eyelids-today had scared her as much as it had him, whether she wanted to admit it or not. Castle's hand found hers as he snuggled up behind her, lacing their fingers together. Even in sleep, she sought comfort in him, pressing back against him.

Castle watched her, falling a little more in love. It had been no question of him being with her tonight. They'd barely made it through the door before Beckett's hands found him, pulling at buttons and reaching for any exposed skin Beckett could find. Castle was equally as frantic, his hand placed flatly against her heart, feeling the life beating with her. His lips found her pulse jumping in her neck; he felt Kate's heart rate increase as his lips and tongue moved over the sensitive skin. From there it had been a flurry of arms and legs tangled together, the fear of losing each other making their need almost tangible. They joined forces together, the feel of each other's closeness calming their racing fears.

The second time had been slower-Castle had led her to the bedroom and spent the better part of the evening holding her, loving her, showing her how desperately he needed her, how incredibly in love with her he was. Kate returned the feeling in spades, saying over and over how much she loved him. While Beckett had said the words before, she had always been more about subtext. Tonight, she'd used her words. Castle could still feel her breath on his ear as she whispered as the moved together "I love you Rick, I love you." Kate whispered how much she had needed him, how he always calmed her. She spoke of her gratitude for his partnership, his friendship, his love. She marveled at his commitment to staying with her, and her desire to be with him. Sated, Kate had kissed him deeply, saying again the three magic words that made Castle's heart soar, before sleep claimed her.

He finally admitted sleep would not come. Castle climbed out of the bed; Kate shifted at the loss of contact, as if she sensed him leaving. Smiling smuggling, Castle walked through the apartment. His eyes searched without thought, the writer in him causing him to look for details. He glanced at the clock-it was late enough for it being too early to be up to make coffee. He moved effortlessly, her apartment almost as familiar as his loft at this point. Castle found the coffee and started the machine, inhaling deeply as the rich aroma filled the room. Out of the corner of his eye, Castle saw that stacks of laundry Beckett had been doing several nights ago-the last time they had stayed at her place. The red tee-shirt caught his attention. It was hanging up, the only shirt that managed to be placed on a hanger before a murder had called her away.

A sudden memory flashed through his mind as Castle walked over and ran the material through his fingers.

The first time they had faced a bomb together. The complete terror that had filled him as Castle watched her apartment blow up. His elation over finding Kate alive (and he'd be lying if he said he didn't take a peek when he'd found her naked in the bathtub, remnants of her apartment on fire around them.) The happiness when Kate had agreed to stay at the loft. His desire when he'd seen her, cooking breakfast in his tee-shirt, the same one she had hanging up in her apartment.

Her voice brought him back to the present.

"I used to sleep in it."

Castle turned, smiling softly at Beckett. Kate leaned against the doorframe, his dress shirt thrown over her, buttoned just enough so it stayed closed. Kate nodded at the shirt he still held in his hands.

"After I started staying with Lanie, I'd put it on after I told her I was going to bed. I could smell you. I'd picture being back at the loft-only it wouldn't be because of a bomb. I'd wear it on the nights I thought about you. What you would be doing after you left the precinct. The nights when I-" Beckett walked into the laundry room, standing directly in front of him as she continued-"the nights when I would admit to myself that I wanted you, that we were more than partners, that I could picture a life with you." Castle saw her hazel eyes, the ones that had mesmerized him from day one, darken slightly with desire. He imagined his blue eyes looked the same. She pressed her lips to his jaw, saying softly

"There are times now, when we spend a night apart, I still put it on. When I can sit and think about how far we've come. For example-the first time I wore your clothing was because some psycho tried to kill me. Now, I wear your clothes because someone got out of bed and I got cold." She gestured to the dress shirt that barely covered her, drawing a wolfish grin from Castle. He pulled her close, kissing her without reservation. When he pulled back, Castle admitted

"I looked for this shirt after you left. I told Mother and Alexis it was because it was such a comfortable shirt. The truth was…I knew it would now smell like you. It would be a reminder that you were alive, that we still had a shot. If I'd know what was under the clothes then, I probably would have tried to make that shot happen sooner." She punched him softly in the arm, but her smile betrayed how she really felt. He cleared his throat and continued.

"When I couldn't find it, I knew you'd taken it. Thrown haphazardly in a bag with the rest of the clothes that weren't smoky or burnt. But sometimes, late at night, I'd picture you wearing it. After a long day at work or after getting out of a bath…" He pressed the shirt to his face, breathing in the now familiar scent of her that was embedded into the shirt and into him.

Beckett stepped into his arms. Pressing his face into her neck, Castle whispered

"I don't ever want to come that close to losing you again."

"It comes with the job, Rick. I'm going to get into scrapes sometimes."

Her hands danced along his back as her lips pressed tender kisses to his neck. She chuckled slightly and said

"We always manage to come out unscathed."

Beckett pulled back and touched his cheek. The red tee shirt-the one he had loaned her when her apartment blew up, the one she kept, the one that was truly a turning point between them-was held between them. Castle kissed her gently, reminding her once again that he was here-that they were together, that they were alive. There would be scrapes and walls and issues that would arise. But for tonight, the shirt reminded him of how far they had come since that first bomb and the once they had faced this afternoon.

Castle pressed the shirt into Beckett's hands, saying hotly

"Tomorrow night, you wear this at the loft. Let's see who was closer to the truth with their wishings."