John opened his eyes. It was raining outside, again. He sat up slowly and rubbed his eyes. He had to go to work later, but there was nothing to do until then. Without Sherlock, there was never anything to do. His heart sank as the reality hit him, again, that his best friend was dead. The truth was always there in the back of his mind, but the pain never got old.
A loud meow distracted him for a minute. A plump tabby cat was sitting in the kitchen, waiting impatiently for its breakfast. John was almost able to smile again at the sight of their- his, he corrected himself- cat. He remembered how the cat had come to live in 221 B...

An ad in the news caught his eye, a picture of a fluffy kitten with big brown eyes... John squinted and looked more closely. A local animal pound had placed a large ad on the front page asking everyone to adopt dogs and cats from them. John had always had a soft spot in his heart for cats, but he couldn't realistically have a cat here. Not with Sherlock around. Not with such unreliable hours and all. The cat would go mad. And a dog was absolutely out of the question- not that John would ever want a dog. He'd had enough of them at his ex-girlfriend's house.
Where was the harm in asking, though? John decided to bring up the idea after all, just for fun.
"Sherlock?" he said.
"What is it, John? Tell me there's another serial killer around."
"No, actually."
"Oh good God, how long is it going to take?"
"I understand that you're bored, Sherlock, but personally I can't say I'm disappointed that no one's gotten brutally murdered recently."
"Oh, those poor little people, I know, I know," Sherlock mocked.
John held his breath and counted to ten. That was the only way to deal with his flatmate sometimes.
"What do you think about poor little cats?"
"Excuse me?"
"Cats? Do you like cats?" John repeated.
"They disturb my thinking process. They just mess everything up. Mycroft had a cat when we were younger, it hated me for no reason whatsoever that could be explained from my observations. I don't see how anyone can like cats, you do know what I mean?"
"Not exactly, I've always liked cats."
"The answer is no." Sherlock said.
"What? I didn't ask you yet."
"I don't want a cat, John, not even if it's a fluffy kitten from the pound."
John sighed in frustration.
"I thought maybe I could get one for Mrs. Hudson. It's her birthday next week. Do you think she'd like a cat?" he suggested.
"One would assume that if she wanted a cat she would have one by now. But quite frankly, John, as long as I don't have to deal with it, I really couldn't care less about your animal rescue impulses."
John nodded. That seemed to be the best he was going to get out of Sherlock today.

John knocked on Mrs. Hudson's door. The kitten he'd adopted meowed pitifully from inside its box. Her brown eyes melted John's heart, and he couldn't wait to see Mrs. Hudson's reaction.
"John?" she exclaimed, opening the door.
"Mrs. Hudson! Happy birthday. I've gotten you a kitten." he smiled.
"A kitten?"
"Yes, the pound reduced their prices. They're really trying to get their animals adopted."
"Oh, I'm so sorry. I'm allergic."
"You won't take it?"
"No, I can't. You and Sherlock can have it though."
"I'm afraid that wouldn't work out too well."
"Well, you can at least try. I'm really sorry. She does look like a sweetheart."
"Happy birthday anyway!"
"I know, I'm getting older. You don't have to remind me!" she laughed.
She closed the door and John cursed under his breath. What was he supposed to do now?

"Sherlock, we have to keep the cat." John announced, walking in the door.
The detective glanced away from the show he was watching.
"I knew we would." he said.
"Don't tell me you knew she was allergic."
"Of course I knew."
"Why didn't you say anything if you knew I was getting the cat and she couldn't keep it?" John exclaimed in frustration.
Sherlock said nothing. He walked over and looked at the kitten. It meowed at him.
"Meow meow." he replied. "That thing stinks. What a mess it will be."
"It will fit right in with you then." John commented.
"No, we can't keep it."
"Sherlock, I can't just take her back!"
"You don't have to stay here."
"You wouldn't kick me out because of her."
"Wouldn't I?"
"We're keeping the cat, Sherlock. Try not to torture her too much."
"John, can you go get the milk?"
John stared at him.
"Yes. Fine. Alright. Whatever you want Sherlock."
John walked out quickly. He crossed his fingers and prayed that Sherlock wouldn't attempt any horrific experiments on the kitten.

John returned with the milk and the cat food he'd gotten as well. He looked around for the kitten, but she was nowhere to be seen. Sherlock was sitting by the window with his violin, deep in thought.
"Composing again?"
"Obviously."
"What is it this time?"
"I haven't decided yet."
"Where's the cat?"
Sherlock laughed.
"Sherlock, where is she?"
"I never said I was going to watch your kitten for you, John."
John sighed in exasperation. He picked up the pillows on the couch, looking in possible hiding spots for the kitten. He stopped himself from meowing just in the nick of time. Sherlock would never let him forget it if he meowed in his presence.
"Sherlock, are you sure you haven't seen her?"
Sherlock turned around in amusement. And then John saw it- orange cat hair, on Sherlock's purple shirt. John laughed. Sherlock frowned in confusement.
"What's so funny?"
"Sherlock Holmes, you have cat hair on your shirt."
He brushed at it with his long fingers.
"No, I don't."
"Don't be an idiot, it's as clear as day. You were playing with it, weren't you?"
"To be more accurate, it attacked me."
"But you don't know where it is?"
Sherlock shrugged and returned to his violin. Then John heard the most pitiful of meows.
"Sherlock, shut up, I heard it."
Sherlock proceeded to play more loudly than before. John looked around and saw movement in Sherlock's coat, which was thrown on the couch. The little kitten crawled out of the sleeve.
"Kitty!" John exclaimed. "Sherlock, I think she likes you. Or your coat at least"
Sherlock put his violin away and picked up the cat. John froze for a minute, preparing himself to defend the helpless kitten. Then Sherlock started giggling like a little kid. He pet the cat and mumbled under his breath to it. John stared.
"Are you friends now?" he asked.
"We've always been friends." Sherlock answered. "We're keeping him."
"Him? It's a girl."
"The pound was wrong, then. I'm astounded you didn't notice. You are a doctor."
"I'm not a veterinarian."
"You still should have noticed."
"What else do you know about him?"
Sherlock studied the kitten.
"He's about five months old... used to have fleas, but the treatment actually worked... one of a large litter, perhaps seven or eight... came out of an abusive environment..."
"Brilliant."
"John, I do believe you've saved the life of this cat."
John smiled idiotically at Sherlock and the cat.
"Are you going to name him? You love naming your blogs, so surely you can come up with a name for a kitten."
"Oh, I haven't even thought about that yet. Why not a simple, sensible name?" John suggested.
Sherlock laughed.
"No. This is the best cat I've ever met. It deserves to have the name of the best man I've ever met."
"What?"
"John. His name is John."
"Won't that get confusing?" John blushed.
"Do you have a better idea?"
"Well. If we're naming it after extraordinary men, I would name it Sherlock."
The detective and his blogger looked into each other's eyes briefly, and then turned to the kitten.
"I suppose Sherlock might get confusing as well." John muttered.
"We can combine names. We'll call him... Johnlock." Sherlock said loudly.
"Johnlock. That's... that's brilliant."
"I know." Sherlock smiled.
And that was how Johnlock the kitten came to live on Baker Street. In fact, he soon became the most liked and spoiled resident of 221 B...

… John's heart broke as he remembered Sherlock's happiness on that day. He stumbled to the kitchen to fill Johnlock's food bowl. The cat was growing up nicely, he realized. Even in the darkest of days, John knew he still had to stick around. He didn't have anyone left for him in the world but Johnlock, and he would stay with Johnlock until the end.