Kate Beckett closed the door behind her with a sigh, exhaling in quiet relief. The day had gone smoothly, but slowly, and she was glad to be finally home. The most action she had experienced was Esposito cursing under his breath when his vending machine snack had caught against the curly hook and refused to be released. The rest of her day was spent catching up on paperwork from the triple homicide they had wrapped up the afternoon before.

Quickly and efficiently, she secured her Sig Sauer and badge in the metallic wall safe. As she shut the door with a satisfying click, she felt something slam into the backs of her legs.

"Mommy!" an excited, demanding voice cried out. Kate pressed her hands against the wall to study herself against the sudden shift in her center of gravity. Glancing down, she found herself staring into a pair of big blue eyes, partially obstructed by an unruly mass of light brown curls. Small hands curled tightly into the skin above her knee, and Kate smiled affectionately at her exuberant son.

"Andrew!" cried the scolding voice of her husband, who skidded to a stop in the study at the sight before him. "Oh, hi Kate!" he said.

"Hey yourself, Castle," Kate said, smiling and accepting the quick kiss he offered her in greeting. "What are you two doing?" she asked amusedly, taking note of her son's Halloween costume. It was July.

"There's been a murder," Andrew said solemnly, his blue eyes wide and serious.

"Oh, I see," Kate answered him gravely as she nodded in understanding. Her eyes flashed to Castle, who had his lower lip tucked between his teeth in an attempt to hold back the smile that threatened to break free. "Is that why you're dressed in your police uniform?"

Her son nodded and tugged at her pants, leading her to the living room. As Andrew explained the unfortunate circumstances surrounding Teddy the Bear's unlucky demise, Kate cocked one eyebrow and stared at her husband, gesturing to the scene before her.

Teddy the Bear's cuddly body was arranged haphazardly on the wooden floor. White tape had been used to outline the bear's body, and an assembly of "officers" in the form of action figures was placed strategically at the scene of the crime.

Castle shrugged at Kate with a laughing gleam in his eye. "What can I say?" he asked her with a grin. "He has his father's flare for the dramatics and his mother's interest in detecting."

Kate crossed her arms over her chest and nodded to her son. "Have you spoken to Teddy's family and friends?" she asked playfully, squatting next to Andrew on the floor. As he rattled off the details of his "case," Castle supplied his own interesting and outlandish theories about which toys might benefit from Teddy's ill-fated downfall. Together, the three of them immersed themselves in finding justice for the stuffed animal.

Later that evening, after Andrew had gone to bed, clutching Teddy in his arms – as it turned out, it had been Teddy's twin brother Freddy who perished, and not their son's beloved bedtime companion – Kate settled between the silk sheets of her bed.

As Castle climbed in beside her, he smoothed the hair back from her forehead and pressed a soft kiss to her temple. "You're truly amazing," he murmured in her ear. The low timbre of his voice caused goosebumps to form on Kate's arm, and the sweep of his thumb down the smooth column of her throat had her stomach coiling pleasantly.

"Because I helped our son solve his fake murder mystery?" she asked wryly, letting her fingers curl around the fine hairs at the nape of his neck.

"Because you indulge him – the same way you indulge my theories and help me with my novels." As he spoke, he trailed his fingers reverently across her collarbones, sweeping her sleep shirt aside to press a soft kiss to her shoulder. "You're a good mom," he concluded softly.

She felt her heart swell with love and admiration for this man. He was an amazing father, which she had known since they first began spending time together all those years ago. But now she had the privilege of experiencing firsthand what an astounding dad he was to their son, Andrew. He was the kind of dad who spent countless hours setting up a fake crime scene for a murdered teddy bear and then enthusiastically participated in the fake investigation.

As she turned to face him, she kissed his mouth slowly, gently pulling his bottom lip between hers. "You're an amazing dad," she whispered fiercely. "And husband."

"Amazing, huh?" he grinned playfully, using his tongue to tease the shallow dip of skin where her neck met her shoulder. She groaned quietly when he slowly trailed his tongue up her throat, arching her neck against his mouth and massaging her fingers at the base of his head.

"Yes," she whispered breathlessly.

As his mouth ascended from her throat to her jaw, Castle stopped just short of kissing her lips. Gently, he cupped her chin with one hand and turned her face so that she was looking in his eyes. "You," he said quietly, "are the best mother I could ever hope to have for my child. And the only woman I want as my partner for life."

The sincerity in his eyes and voice stole her breath away.

"I love you," she whispered as his lips finally touched hers in a tender caress. "Always."