Prompt: Castle commissions a copy (with real gems) of the Blue Butterfly for Beckett.

This was going to be the best anniversary gift ever.

Castle had wracked his brain for the last two weeks, trying to think of just the right gift for his wife on their first anniversary. Something that showed her, beyond the shadow of a doubt, just how much it meant to him to call her his wife. Not that he doubted that Kate knew — they'd spent plenty of time this first year expressing their love and gratitude for one another.

Those old stories about married life causing things to cool off were wrong; if anything, being married had only turned up the proverbial wick. Especially once Martha and Alexis moved out of the loft.

Now that Kate was expecting their first child together — she was roughly a month along — he wanted the gift to be all the more special.

And it would be an actual, physical gift; as tempting as it was for Castle to get Kate back for the fake murder she set up for his birthday a few years back, he wanted their first anniversary to be more special than that.

Castle had come up with the perfect idea, but he found executing that idea to be more difficult than he'd expected. It took practically every "guy" he knew to pull off this particular gift, and until the wrapped box wound up in Castle's hands the previous night, he had been nervous to the point of sweating that he wouldn't be able to pull this off.

But he had. This was going to be perfect. It had to be.

Part of Castle wished he could've accompanied Kate to the precinct today; it was obvious that morning, based on her mood, that she didn't want to be apart from him. But with a loving kiss and a promise, Kate relented, letting her husband go about the business of his day while she and the boys worked the precinct.

Miracle of all miracles, a body didn't drop. Yet she was still exhausted when she walked into the loft, huffing a sigh as she tossed her coat over the railing of the stairwell. She scanned the kitchen and the living room for her husband, frowning when he wasn't there.

But she did see the wrapped box on the island in the kitchen, with a note attached that read Come to the office - don't open this yet. A smile tickled the edges of her mouth; even when she was rundown, he still managed to lighten the load.

It was all Kate could do to keep from laughing when she walked into Castle's office and saw him perched at his desk, wearing the hat she had given him when he opened his P.I. firm, the magnifying glass resting on the desk. He turned to regard her, a half-empty glass of scotch swirling around in his other hand.

"And as if Lady Luck finally decided to smile down upon me, she walked in," Castle somehow managed to keep a straight face as he, once again, slipped into his noir voice. "The girl of my dreams, my femme fatale in every sense, the doll who lights up my nights even as the rest of the city is enveloped in darkness."

Despite her best efforts otherwise, Kate grinned from ear to ear. "This is my anniversary present? More noir roleplay?"

Castle must've been really excited, because he actually broke character, removing the hat from his head and putting it back on its post, atop the lamp on his desk. He lifted himself from his seat, closing the distance between himself and Kate before cradling her neck in his hand and greeting her with a loving kiss.

"Not exactly." The smile on his face was infectious, even as he head-nodded toward the box in her hands. "But…it will make sense once you open your present."

When she finally opened the box in her hands, Kate gasped and brought a hand to cover her mouth. Her hazel eyes were wide when they met her husband's, that twinkle she loved so much on full display. She again regarded the necklace in her grasp, marveling at both its beauty and familiarity.

"Castle…"

"The Blue Butterfly," he announced. "Well…not the Blue Butterfly, but the gems are very real."

Kate watched as Castle carefully lifted the necklace from the box and approached her from behind, positioning the necklace in the right spot before clasping the chain around her neck. Kate's hand instinctively went to the heavy pendant resting on her chest, the marvel still in her eyes.

The marvel entered his eyes when he saw the necklace on her, his hand roaming up her arm before giving her shoulder a squeeze. "Beautiful…"

"Castle, where did you get this?"

A shrug of nonchalance. "Let's just say I owe a lot of guys a lot of favors." Castle gave her shoulder another squeeze. "But that's not all…do you still have that dress you wore at the launch party for Heat Wave?"

Kate's brow scrunched in confusion. She hadn't worn that dress in years. "Yeah…why?"

"Because I booked us a reservation at one of New York's most upscale restaurants, and I think your new necklace would complement that dress wonderfully."

A twinkle of mischief flashed in Kate's eyes. "You sure you don't just like the way that dress hugged my curves?"

Another shrug. "That too."

Kate huffed a laugh into another kiss, this one longer than the last, and she was already accustomed to the weight of the necklace. When the kiss broke, she wrapped her arms around Castle's waist as he brushed a strand of hair out of her eyes.

"Happy Anniversary, Mrs. Castle."

She hummed in contentment against his chest. "Happy Anniversary, Mr. Beckett."