Final little author's note: This story was an epic adventure for me. It was the first time I'd ever consciously sat down to write something so long, and it was the first time I really had an extended plot in mind when I started writing. (It's actually not the longest thing I've ever written, but it the longest thing I've written on purpose). I've always loved period pieces and historical AUs but I've never really been game enough to try one until now. This idea just wouldn't let go. Needless to say, I can only hope and pray we get a noir episode this season! Anyway, I did quite a lot of research and I wrote a little bit about the making of here, if you're interested. (Wow, I know, I really like to talk about myself, don't I?)

Thank you to everyone who's perused. I really am grateful for every reader and to those who commented, my special thanks. It's always nice to know that someone liked your silly little idea as much as you did. It's been a really long road, so I congratulate you on making it to the end. I hope this satisfies you curiosities and is befitting the rest of the tale.

Epilogue.

Canada. July, 1926.

There was a deep lake fifty miles from the little town, accessible only by a dirt logging track. He had been captivated by the local legend when they first arrived. At a small diner in the main street a local had told him the tale. Two lovers met on the shores of the lake, a man and a woman both drawn by its beauty. One evening, she was wading in the shallows, staring at the stars and thinking of her beau when, filled to bursting by loving so much, her heart escaped from her chest and sunk to the bottom of the lake. The woman could not swim, but desperate, she tried to follow it, struggling downward and downward until she was so far underwater the surface was indistinguishable from the night sky above. When she caught her heart, she was exhausted and the quiet of the lake bed was soothing. Unable to resist, she clasped her heart in her arms and gave into the tide. The man was distraught; he had lost his greatest treasure, her heart, to its depths. He spent years searching, but could never reach the lake bed. Even when he drowned trying, the currents and laws of physics returned his body to the surface. It appealed to his writerly sense of melodrama and Castle had taken to spinning variations on the tragic tale for travellers passing through. It had some truth behind it at least; no one had ever officially measured the depth of the lake. Many had tried, but it was so deep that their equipment failed. It was thought that it wasn't possible with current technologies.

In the winter, The Great White North lived up to its name. It was bitterly cold and the snow was so deep it made traversing the streets nearly impossible. She never felt truly warm the first year. But that was to be expected. It was the summer weather that surprised her. The heat was sweltering in their little town at the bottom of the valley and there was something about the air that made it impossible to cool down. It was thick and oppressive, like bathing in hot honey.

One particularly acrid day, they made the journey to the lake. They had to leave the car halfway along the hillside when the road got too rocky, and she was beginning to think the unofficial directions he had received at the diner were leading them astray when, after a steep incline, they reached a crest and below them the landscape unfolded, revealing its secrets. Shimmering into the distance lay the lake, the sunlight reflecting off the blue-grey water. At the horizon, a single tall peak, taller than from where they had come, cut up from out of the water. Behind it, the rest of the range was a green blur.

The path to the shore was carpeted by pine needles, and the vegetation thinned out as they descended opening onto a half mile of meadow before the shore started. Walking into the clearing, a little, rudimentary pier constructed of logs tied together by rope came into view. At the end was a small wooden boat with two oars.

Castle walked ahead to untie it while she kicked off her shoes. The ebb and flow of the pseudo-tide had, over centuries, weathered rocks into sand. It filled the spaces between her toes and crunched beneath her feet.

The makeshift dock was rough and bobbed about with each new gust of wind. He held out his hand to help her into their vessel.

"Yarr, welcome aboard m'lady," he did his best pirate.

She laughed and accepted his help, throwing out an arm to steady herself as the wind and water rocked the wood beneath their feet.

"Don't worry," he continued, "You'll soon find yer sea legs."

She took the oars before he even sat down. The sudden forward propulsion nearly sent him headfirst over the bow. She smirked and quirked an eyebrow, an unspokenwho's finding their sea legs now?He settled himself onto the wooden seat quickly and gave her a brief, wounded look. She nudged his toes with hers until he gave up on the act.

When she started to tire, he took over and she let her hand trail through the water as he paddled. Even in the heat of summer, the water remained cool. She flicked some into his face mischievously and set about looking innocent when it hit him. His surprised expression soon mirrored her devilish one, and on the next stroke of the oars he brought a torrent of water up into the boat, soaking her skirt. She shrieked at the shock of it, then, laughing, lunged for a paddle to return the favour. The motion brought them into unexpected proximity, her body bent forward at the waist and their noses together within an inch. Her laughter faded into a small smile which widened when he kissed her.

She let her one hand rest against his neck, holding his face close and he brought a hand up to span her waist, fingers sliding along her floating ribs. Their lips and tongues met in a well-rehearsed dance. There had been hundreds of kisses like this one – stolen and given, illicit and public, lazy and loving and frenzied and fervent – but at the heart of it, they were all the same as the very first time he had kissed her in front of the blackboards in his study. There was the same fast breathing and racing heart and gooseflesh raising the hairs on her arms and there was the same utter wonderment at that afterwards. Time had made it routine, maybe less remarkable, but there was still something about it she couldn't explain. (She thought maybe he could, with his words; he couldn't, though not for want of trying.)

Somewhere in the midst of it, they both dropped their oars. They sank into oblivion, leaving only bubbles of escaping air in their place.

He pulled back and met her eyes, fingers rearranging the damp hair that was whipping at her cheeks in the wind and then, realising something was amiss, stared down at their empty hands.

The laughter was mutual and echoed along the walls of the delta.

They fell silent and he took her hands, squeezing.

"What's eating you love?"

She smiled.

"The captain of a ship can officiate a marriage at sea, correct?"

He looked at her in surprise. "Actually I think that's a very well-entrenched myth."

"Castle," she gave him a look.

"If this is a ploy to get a ring out of me, you know I'd buy you anything," he teased until she pinched him.

"Stop interrupting me," she flustered. "I'm trying to say something important."

"Yes ma'am," he rubbed his arm.

She pulled the chain out of her dress and fumbled with the clasp, finally prising free her mother's ring that she had carried for so long. She reached for his hand and pressed it into his palm. "I want you to give it to me."

"Are you asking me to marry you?" he looked at her with wide eyes.

"I'm telling you I love you, you sap. And I want you to put that ring on my finger and tell me you love me too."

"You know I do," his eyes were serious, finally. It was the first time she had ever told him she loved him in as many words; he had been mostly happy to just assume she did. He took her hand in both of his and slid the ring onto her finger. "I promise you I always will."

"That's enough of a marriage for me," she told him, leaning forward and kissing him softly. She crawled across the boat to sit beside him, letting him tuck her under his arm and press tiny kisses against her hairline.

"You love me huh?" he murmured against her temple. Her head was resting in the crook of his shoulder and his hand was stroking her hair at a languid pace. She yawned, warmed by the sun and comforted by his rhythmic ministrations.

"More than anybody else," she confirmed.

"Well, I've long suspected, but it's nice to hear you say it."

There was a long pause, punctuated by the wind stirring the water into little waves that lapped at the hull of the boat.

"How will we get back?" she wondered, shielding her eyes from the sun to appraise their distance from the shore. The small diamond in the ring caught the light as she did it, scattering sunbeams across their entwined shadows. His chest ached for how full it was.

Castle grinned at her, stood and offered her his hand.

There was a lake fifty miles from nowhere that was so deep no one had ever touched the bed. Its deepness defied measurement and looking into down into the water, it seemed limitless.

Katherine Beckett accepted his hand, took a deep breath and jumped.

Fin.