Castle breathed in and out nicely besides Beckett. Rhythmic. Soothing. He seemed exhausted from the day when they got in, so she wasn't all too surprised when he turned in early. She didn't mind. It gave her the opportunity to just watch him rest, to care to him. She enjoyed watching his chest heave up and down, his lips sometimes parting, sometimes just moving, like he was still trying to talk to her in his sleep. He'd mumbled her name quite a bit already. Like he wanted to tell her something, to let her know what was happening with him, so she could be a part of whatever he dreamt.

After just looking and observing for several minutes, she inched towards him, rested her mouth against his shoulder, and hummed. It was a low, slow hum. She pressed it through a smile as she pushed back his hair, rocking his head back like she were keeping him asleep. She didn't feel the need to sleep herself just yet. She could do this all night if she could. She hummed away and ran her fingers through his hair, grazing his scalp with a ginger touch. She never really got this opportunity to appreciate him sleeping. She would always fall asleep first. This was different, and it was wonderful, and it was joy. Because this was the guy. He was the guy. He was the guy who loved her. She would always think fondly on that.

When she started to slow her hum, he unsettled a bit, turning away from her onto his side. There were more ways than one to mess with him, so she didn't fret. It was all a matter of finding a good spot.

This time she took to his back. She neared the space close to the back of his neck, and made her way down in slow strokes. She traced over his skin with her one index finger, while the left hand had grabbed for his and rested them at his hip. She enjoyed this very much. It was a kind of soothing peace she hadn't felt for a long time. She could go the whole night, and she would feel bliss, she would feel comfort. Being together, resting together, their hearts synced up and it was like they were one. They were. They were one.

And so she remembered a song. As she continued to trace along his back, she lost herself in what she wrote on his skin as she sang to herself very quietly.

Every night together, every morning we wake

Make sure we both remember, our hearts we've gotta take,

I'll hold yours and you grab mine at the start of every sun

We'll keep 'em close forever, when each and every day is done

You're the warmth of every moment

You're the breaths I want to breathe,

You're all I ever wanted

And you're all I'll ever need

Kiss me when you wake up, even without all my make up

And we'll brave another day We'll always find our way,

Cause always saves us from the end

So our love can live again

So today's will have their happiness

And tomorrow's with their hopefulness

And together our wholeness will never have a doubt

There's one in me and you,

Only one between us two

So lost in her little tune, she was starting to drift off. In her daze, she realized her finger had repeated tracing on loop I love you almost automatically. Acknowledging this, she brought herself to finish off her last trace, and smiled tenderly to herself. She pressed her lips firmly into her canvas, sealing everything she wrote deep into the pigments of his skin.

Overcome with her sudden tiredness, she turned to face the ceiling and closed her eyes.

Next to her, Castle turned his head to look over at her, and too gathered a smile. He took her hand that still linked with his, and he kissed it as he repositioned himself. He turned to face her and brought himself around her, cradling her head with his one arm on her pillow, the other over her stomach, and the rest of his body linking up to hers, every crevice hooking together. Skin to skin. Bare, raw, and warm. He closed his eyes again in attempt to fall back into his deep sleep, but he knew he had to say something. Before he could, after being slightly startled by his motions, she opened her eyes again and turned to him with a sleepy gaze, and cupped his cheek with her hand after realizing his consciousness.

"I love you too," he said fast, before she could gather a word herself. He waited, expectant, for some response from her, but when he peaked open his eyes, she fashioned a smile with high brows. "I thought it'd be rude not to say anything after you wrote it—forty-seven times on my back…and yes, I counted."

Her smile grew and it shut her eyes, but it melted when he bent his head to kiss her. He lingered, singing his own version of I love you into her mouth. She returned it, before nestling herself into his chest.

"Goodnight babe," she spoke into him.

"…There's one in me and you," he echoed, "only one between us two."

And with time, they both drifted off, lulled to sleep by the pulse of their love running through them as readily as their blood; the beat of their hearts, drummed and synched into one beat, supplying each other the very same life. It was as if they melted, melded together, incapable of ever truly separating again.