John had no idea how Sherlock felt about animals. Or Mrs. Hudson, for that matter, but he imagined it wouldn't be too difficult to convince the landlady to let the poor thing stay. After all, who didn't like dogs? It briefly occurred to the doctor that Mrs. Hudson might be allergic, but it was a bit too late to turn back now.

"You're late and we're out of hydrogen peroxide," Sherlock said blankly when John walked through the door, too busy reading the newspaper to look up. It took him all of two seconds to realize his partner wasn't alone. "What is that?"

Not exactly the reaction he'd been hoping for, but John figured there were worse ways Sherlock could have handled the news. "It's a dog." When Sherlock didn't say anything, he went on. "She was out on the streets all alone, and when she started following me I didn't know what to do. I took her to the veterinarian and they said nothing was wrong with her besides being a little underfed. All of the nearby shelters are full, so I…" John trailed off and gestured to the dog as if that answered everything.

"A dog."

The newspaper was on the coffee table now, so at least he had Sherlock's full attention. Still, John couldn't tell what his partner's opinion of the whole thing was. Confused? Angry? Amused?

"Yes, Sherlock," he said with an audible sigh. "A dog."

The happy mutt left John's side to approach her new master, rubbing her head against Sherlock's leg in an attempt to get him to pet her. It didn't seem to have any affect on the man, though, who stared blankly at John. Unhappy with the lack of attention she was getting, the dog let out a small bark and jumped up so her front paws were on Sherlock's lap.

"She wants you to pet her," John said, wondering what was going on through the famous detective's head.

"I know."

John shook his head in desperation and sat down in the chair opposite of Sherlock. "Tell me what's wrong."

"I don't—" he hesitated, something John rarely saw him do. "I used to have a dog."

"Oh?" It wasn't very often Sherlock spoke about his childhood, but John had always wondered what he was like growing up. A few weeks ago, when Sherlock's parents came to visit in order to meet their son's new boyfriend, Sherlock had kept the dinner as short as possible. Something John thought was unfortunate - they'd be wonderful people.

"He died."

"Oh." Well, that would certainly explain the strange behavior. "What happened to him?"

Sherlock was looking at the dog now, who had since padded back over to John's side, knowing she would at least find some affection there. "He was hit by a car. I was twelve."

"That must have been difficult," John said softly. "I'm sorry, I should have called you and asked if you were alright with me bringing home a dog. I'll find her a new home as soon as possible, but are you alright if she stays here for the night?"

"Fine," Sherlock said a little too sharply. "Tomorrow it's gone."

John frowned a little bit, wishing he could think of something to say to change Sherlock's mind. It really was a beautiful dog, even if she was just a skinny stray, and so sweet. But it was Sherlock's flat, too, and he wasn't going to force anything on him.

"I'm going to make dinner, then," John announced. "Do you mind keeping an eye on her? You don't have to do anything besides call me if she starts doing something she shouldn't."

Sherlock nodded and sent him off with a wave before turning his attention back to his newspaper. John spent the next half an hour in the kitchen, so focused on making dinner that he didn't notice the relative silence of the flat. When he walked back out to announce that the food was ready, John saw the dog half sprawled in Sherlock's lap while Sherlock held a book in one hand and petted her head with the other.

"I was thinking about Atalanta," Sherlock said without looking up from his book - or bothering to stop petting the dog, John noticed with a small smile.

"Excuse me?"

"As a name. We can't keep calling her 'the dog', now can we? Atalanta is a character from Greek mythology - a huntress who swore—"

"I know the story," John said with a grin. "Does this mean you want to keep her?"

Sherlock tried to look stern, but his lips were curling upwards. "Consider it a trial run."

John walked over to him and kissed him, grinning widely. "You sure?"

"It's only a trial, John," Sherlock reminded him quietly, although he was still petting the dog's head. "But we can't go on calling her 'the dog' now can we?"

Atalanta was looking up at them curiously and let out a quiet bark to remind them she was still there.

"We're going to have to get her to stop that if we want Mrs. Hudson to even consider the possibility of her staying," Sherlock said with a sigh.

John tried to hide his grin — he would have to go to the pet store tomorrow.