Summary: AU. Dean and Castiel adopt a little girl with some serious issues, and find themselves having more on their hands than anticipated, and Castiel finds himself having to prove that blood, or in this case bond, is thicker than water. Please R&R!

Disclaimer: I don't own Supernatural or its characters. I only own Grace Winchester.

A/N: A new, angsty and slightly dark Destiel AU fic. It should be very fluffy in places but the angst will begin to build gradually between the two of them throughout, however regarding the little girl, the angst is constant. Hope you enjoy!

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Thicker Than Water

Chapter One

The children's home was so bright and colourful, it even made Dean and Castiel smile.

They were going to finally take home their new daughter. Grace Winchester, formerly Grace Adler, was just two years old, yet already her life had been full of horror and tragedy. She was a frightened child. A tortured, weak, vulnerable child.

Her mother had been beaten and murdered right before her eyes before her father had shot himself in the head, leaving her crying and screaming until someone else came to help her. She didn't speak much, and got scared over tiny little things. She'd flinch if someone went to touch her and she couldn't go to sleep alone, yet the little brunette with chin length curls found solace in Castiel. As soon as he'd appeared in the doorway of her room she'd felt okay to approach him, and the manager of the home, Ellen Harvelle, was surprised by her sudden lack of her usual fear and shyness. Ellen met the two in the doorway and smiled, gently pushing Grace from behind her.

"Hey, Gracie..." Castiel whispered softly, kneeling down as she edged towards him clutching her cuddly rabbit with her thumb in her mouth, "We're here to take you home, sweetheart."

She let him wrap his arms around her and she just rested silently against his shoulder. No sound, no apparent emotion. Just a blank, pale face. Castiel picked her up and kissed her head, his love for her just filling him with warmth as she turned and buried her face in his neck, her little arms going around his neck. She clearly needed so much love and he and Dean knew that they could give her just that.

"Hey, tiger." Dean said softly, watching as she looked over Castiel's shoulder at him, "You ready to come to our house now?"

Grace nodded softly and cuddled back up to Castiel, Dean taking her bags and thanking Ellen before the two took her out to Dean's baby, his '67 Chevy Impala. She'd been his from his eighteenth birthday, and he took really good care of her. But now there was an even more important baby in his life. Grace. He'd made some adjustments on the car to fit in a car seat for her, and he'd also made some tapes of soothing music for her on the ride home. They knew that she'd been through a lot, and that she'd shown some signs of having further issues that they may need to see a doctor about in the future, but they were okay with that. She needed love and care, and the two of them were more than willing to provide it for her.

"Are you okay back there, darlin'?" Dean asked, earning a silent nod from the little girl, "Just let us know if you need anything."

Castiel smiled at Dean, the two deciding not to share the kiss that they wanted to until Grace wasn't in the way. They didn't want to have that kind of affection in front of her just yet. She knew that they were together, because Ellen had explained that sometimes a girl can love a girl and a boy can love a boy, and that some children have two mommies, and that some have two daddies. It was something that Dean and Castiel were trying to be careful and sensitive about since she was just two, and she probably wasn't used to seeing children with two mommies or two daddies, never mind actually being one of those children.

Dean played his slow rock ballads, and Castiel caught Grace smiling through Nothing Else Matters by Metallica. Dean also saw the smile on her face, and it made him feel fantastic. His baby was already a Metallica fan.

When they reached home, Castiel took her inside while Dean got the bags, taking them straight to her bedroom.

They'd decorated their guest room in a light shade of pink, since she'd shown Castiel that it was her favourite colour, and the floor was covered with a pink carpet. Her bed was like a princess's bed, and it had a little canopy over it so she felt like a real princess when she went to sleep. She had a light wood toy chest, and there was a white rocking chair by the window where they would rock her to sleep on a night until she felt comfortable going to sleep by herself.

Ellen had explained how the care staff had been rocking her to sleep since she'd arrived there, and how she'd never settled into the routine of getting herself to sleep. Castiel knew a lot about the stars and planets, so he could tell her lots of things when they were getting ready for bed time. He'd planned out a daily routine and it was stuck on the refrigerator in the kitchen. He'd decided to leave his job at the local school to take care of her, and since Dean's garage was doing so well, and since they had a decent amount of money stored away, the two found that they'd be able to afford to have Castiel at home looking after her.

Her clothes were in her light wood closet, and in her chest of drawers, which had a Disney princess night light on it. One of her walls had a special display board on it, and Castiel, from his many years of experience working with children, had created her own personal display for her pictures and the other activities they carried out at home. She had a small doll house in the corner, a playhouse set by the rocking chair and a dress up area near the closet. Dean smiled as he looked around the room, and he knew that when Grace got settled, she'd love that room.

Downstairs, Castiel was letting Grace explore her new home, and as she gently stepped through the house, she looked at everything that there was in it.

"This is Daddy and Papa," Castiel said softly as she looked at a photo on the coffee table, "From when we were younger."

She smiled as she touched it, taking Castiel's hand again and clutching her cuddly rabbit, Carrot to her as they moved into the kitchen.

"And this is where Papa will make all your meals, and where Papa and Gracie will do some baking." Castiel said softly, "Does that sound fun?"

Grace nodded and let Castiel take her back through to lead her up the stairs, opening and closing the baby gate as they went. He showed her the bedroom where he and Dean slept, before taking her to the bathroom, letting her see where it was and to have a look around it.

"Do you want to see your room?" Castiel asked, earning a soft nod from the little girl, "Daddy and I took a long time getting it ready because we wanted to make it perfect for you."

He let Grace walk in first, and watched as she gasped at the sight of her new room. She beamed and rushed towards the playhouse set, immediately picking up the little baby that lay in the small crib and holding it close to her. Castiel smiled as she approached him, kneeling down as she cuddled up to him.

"Do you like it?" He asked, earning another nod from the tiny girl who pressed a little kiss to his cheek.

As she went to Dean, she stretched up her arms, and he picked her up to hold her close, gently kissing her temple.

"What do you think, baby?" He asked, "Did Papa and me do a good job?"

Grace nodded again, settling against Dean who took her to play in the dress up area while Castiel continued to unpack her things.

That night, Castiel sat rocking his little girl back and forth in the chair by the window, humming Amazing Grace to her to soothe her into sleep as she yawned tiredly and snuggled against him. When she finally fell asleep, he went to put her into bed, laying her in her new bed and tucking her in along with Carrot and kissing her goodnight.

"Night, Gracie." He whispered, "I love you."

Dean appeared in the doorway, approaching the bed and kissing her goodnight too.

"Night, gorgeous." He said softly, "I love you too. Papa and Daddy are gonna take good care of you."

She snuggled into her pillows and the two left her, content to leave her to sleep before they headed downstairs to spend some time together.

-TBC-

Hope you enjoyed!

Thanks for reading so far!

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