Sherlock's POV:

They wanted him to watch her.

He stared at the energetic two year old. What on earth was he supposed to do with her? She waved her chubby fists and smiled, blissfully unaware that her parents were nowhere in sight. Sherlock threw up his hands. For goodness's sake! Weren't parents supposed to take care of their own children? This is why he despised marriage.

Rosie was actually pretty cute, he had to admit. She looked a lot like Mary, with her sweet face and blond hair. But she had John's serious blue eyes and chin.

As if she'd felt his gaze, she turned towards him. Her stare was filled with pure curiosity, and it made him want to laugh and scowl at the same time. Babies! They were so small and innocent, and they didn't know anything about what the world could do to them someday.

Rosie tried to climb on his lap. He attempted to pry her off, but she held on stubbornly, gripping his shirt. He sighed and picked her up firmly, placing her back on the carpet.

He reached into the bag Mary had given him, filled with stuff to keep her occupied until bedtime. He grumbled as he rummaged through it.

John and Mary's usual babysitter was sick, and they couldn't cancel their plans. And what was John's brilliant idea? To drop baby Rosie with poor unsuspecting Sherlock, who was just going out to check an exciting murder scene!

He finally pulled out a bag of colorful blocks. He opened the bag and put it in front of her. He crouched next to her and wagged one of his fingers in her face seriously.

"Play with these and leave me alone. I have work to do."

She stared at him as he went to his table and picked up his chemicals. She pushed her blocks around for awhile. Boredom was written across her face, but Sherlock was too busy absorbed in his research to notice.

Would he have cared anyway?

Unnoticed, she picked herself off from the floor, and ran to explore the new room.

She had picked up a bag of toes, rummaged through Sherlock's case files, and broken one of his spare beakers before he noticed. It was the noise of the glass shattering that brought him to his senses.

When he stared at the mess, she lowered her eyes guilty. But her guilt vanished at soon as she saw the skull sitting on Sherlock's shelf. She ran to it, her hands outstretched.

His back was to her as he muttered angrily, cleaning up the the shattered glass. Standing up, he almost dropped it again when he saw her fumbling with it. He put away the dustpan and ran towards her hastily. She was trying in vain to fit his precious skull over her head when he reached her.

He yanked it out of her hands. Surprise clouded her face, but soon, tears were making their way down her cheeks and she was wailing loud enough to wake up the world.

He picked her up gently and placed her into his armchair. Placing a rattle into her fingers, he spoke to her soothingly.

"I'm going to get you a bottle of milk, okay? It's probably time for you to sleep anyway."

He made his way to the kitchen, grabbing Rosie's bottle from the bag as he went. Turning on the stove, he poured milk into a pot, letting it heat up. He hummed quietly as the steam started to rise.

He poured the warm milk into the bottle. Just when he was about to close it, he opened it again. Making his decision swiftly, he opened one of the kitchen cupboards and got out the bag of sugar.

He stirred in a small spoonful and closed it. Rosie was strangely quiet when he returned to the living room. She was shaking her rattle slowly and staring at it thoughtfully.

She glanced up at him when he saw her. Her big, round eyes looked so much like John's, he was having trouble looking at them.

He picked her up and sat down, placing her on his lap. He offered the milk to her, but she turned her nose up to it. She started to whine and fuss when he gave it to her. She was struggling against his grip, trying to escape from his arms.

He sighed with defeat and stood up with her once more. With a sudden stroke of inspiration, he made his way to John's armchair. Sitting down, Rosie became quiet again. This time she took the bottle from his hands and started to drink.

Her eyes widened when she tasted the sweetness of it. Sherlock laughed quietly at her reaction.

"I thought you might like it."

As if to thank him, she lowered her head on his shoulder and closed her eyes blissfully. He jolted slightly, surprised.

He started to talk to her. Most of it was nonsense, and he knew it, but she didn't seem to mind. She had the same kind of patience as Mary did.

"You know, you have remarkable parents. John is the greatest man I know, and Mary it just as good. I didn't like her at first. I thought she was taking John away from me, especially for the two years I was gone. But I get it now. They support each other, and I vow to protect them with my life."

He smiled. "That includes you."

He nuzzled his nose into her soft hair and sighed. Soon, her breathing slowed and he had to take the bottle gently away from her dangling fingers.

He sat there for a long time.

And that's where John and Mary found him, Rosie cuddled into his chest, Sherlock with a small smile playing on his face. They were both sleeping peacefully.

And don't tell a soul, but John still has a copy of the picture he took, even though Sherlock made him delete it when he woke up.

Fin