Warning: Mentioning of Sherlock doing lethal experiments on a fish.

Christmas past, so did new years and Sherlock's birthday. Winter turned to spring and the snow melted of the streets and rooftops, but he still hadn't picked up the phone to call his brother. And he wasn't planning on doing it soon either. Hamish seemed to have forgotten about it as well, he spent many hours in front of the piano everyday and Sherlock was proud to announce that his boy had an ear for music. Just the first week with the instrument, he'd learnt the melodies of his favourite tv-shows and now it was all they heard in the flat. He was still disappointed on his fingers though. To short, he complained angrily as he tried to add the chords to the melodies.

Still, Sherlock and John loved to watch him being so hypnotised by the music. He started to listen to Sherlock's old records of classical music. Beethoven was his favourite at the moment, he listened to "Adagio Molto Expressivo" at least four times a day and never grew tired of it. He loved it.

But then one day, when sun was shining bright and the temperature rose over 10 degrees outside for the first time in months, he just stopped. The piano wasn't played and neither was Beethoven. The boy was busy, running up and down the stairs and Sherlock watched from his armchair as he made his way into the kitchen, found an old shoebox under the counter and disappeared down the stairs again.

Sherlock went back to his book and decided to let the boy do whatever he did. It was his business and he wanted to share it, it was up to him. An half an hour later, he came running up the stairs again. Sprinting into the kitchen and pulled a chair over to the fridge to reach the handle.

"Don't open the containers with blue labels!" Sherlock reminded him as Hamish put his head in the fridge.

"I know!" he answered and looked amongst the sandwich toppings and leftovers. "When's daddy coming home?" Sherlock, with his photographic memory, knew exactly what the planner on the wall said.

"Some time after six." he answered and turned the page, not really concentrating on the words anymore but now more interested in what Hamish was doing, but he still didn't ask.

"Where's his medical bag?" Hamish continued and placed a piece of paté and a slice of ham on the table.

"I guess under the sink in the bathroom. What are you planning to steal from it?"

"Nothing!" he lied and ran away from the kitchen, leaving Sherlock with a smirk.

"Don't take anything poisonous or sharp, alright!" he shouted after him and turned the page, listened eagerly to the sounds of Hamish poke about in the cabinets. There was a sound of a zipper, then bottles rattled and followed by the rustling of plastic. The deduction was that Hamish was looking for bandages and plasters and with that, Sherlock had a clue what the boy was up to. He closed his book and raised from the armchair, made his way through the flat and found Hamish on his knees by the medical bag in the middle of the bathroom.

"I can't find the gauze." he complained and looked at the pictures of breathing masks and eye cleaners on the small packages. Sherlock stood in the door, overlooked the mess of containers and bottles and crouch beside him.

"Wrong bag." he said and pulled out a large, green metal box from under the sink. "There in here." The lid popped open and he picked up two packages of sterile gauze and looked at Hamish, observed his clothes hand hand. "How badly is it hurt?" The boy twitched, looked up with big eyes and as always surprised when his father knew exactly what he was up to without being told a word. Sherlock smirked and pointed at his dark green cardigan. "There's fur on your clothing, scratch marks on your left middle finger, but you're not bleeding, and neither does the cat so I would guess the cat's broken something and not wounded in some other way. In that case we might need to give it a splint." He found the wooden splints in the small metal container and gave them to the boy who smiled broadly, he always got chills when his father guessed right in so many ways.
"Will you help me?" he asked and put the supplies in his small pockets. "It's in the shrubbery in the backyards. I think it fell from the neighbours roof."

"Why do you think that?" Sherlock required and followed the boy that hurried out of the room.

"Because I don't think he's moved since the fall."

Hamish reached for the plate of meat when Sherlock cleared his throat and nibbled his bottom lip.

"I think it will be pretty hard to treat a cat in the middle of a shrubbery. Leave the supplies up here, we'll bring it up."

"It's not an it, dad!" Hamish told him sharply and emptied his pockets of gauze and plasters on the table. "It's a he."

"Fine." he groaned and took his hand in his. "Show me where he is."

In the matter of seconds, Hamish pulled him out the backdoor and into the small garden that was so hidden by the buildings around it, it only met sun two hours a day. Sherlock had tried many times to grow spices and herbs in the soil for future experiments, but nothing would grow except weeds and grass. A little camp of a the shoebox was put up by the shrubbery by the left wall of a tall brick house and Hamish released his hand to run over to it.

Neither he or John had sat their foot in this place in ages and he roamed the area with unsure eyes, something was different. Then he saw the new garden furnitures on his right, mrs Hudson had spoken about it. This summer was already planned with garden barbecues and she had spared to expense on making the garden as nice as possible for it. Those furnitures was not cheap, and neither was the grill standing on the grass. He sighed loudly, not liking the idea of spending summer evenings outside with the smell of burnt meat and bugs he had to wave away from the face.

"Dad!?" Hamish shouted, interrupted his thinking. The boy stood on his knees in the mud, spread the leafless twigs and branches and he heard the weak squeak from the animal hiding in there. "You need to help me get him out. He's scared."

He crouched behind him, felt his shoes sink an inch by his weight in the mud and he pursed his lips when he saw the dirty water cover his soles by now.

"Let's do this quick." he sighed and pulled the gloves out of his pockets to not get scratched by the wild animal that panicked by just their presence. Hamish moved out of the way and then he saw the scared little creature recoil and hiss as he reached out his hands. The black fur raised on his back and his long tail grew in size as he tried to look as intimidating as possible.

"It's okay." Hamish smiled and Sherlock stared into the big yellow eyes full of hatred of being disturbed in it's den.

"He can understand you, Hamish." he told him and caught the cat around the ribs and yanked it out of the shrubbery. It screamed in anger and fright, kicked and bite but his thick gloves did the trick to not get hurt.

"Of course he can't" Hamish smirked and observed as his father put the cat in the shoebox and carefully held him down so he didn't try to run, the twisted leg would never manage any sort of struggle right now. "But I think he finds comfort in a calm voice."

Sherlock was sent back four and a half year in time when he heard those words and he gave Hamish a piercing stare. That was exactly what John had told him the first time he held Hamish. Was it just a coincidence?

"What makes you say that?" he asked and stepped out of the mud, still nailing the screaming cat to the bottom of the box and felt him try to squirm. Hamish shrugged and stood on his toes to take a look at the animal with big, interested eyes, stoke it's fur now when it couldn't attack him.

"It just looks like he gets calmer when I talk to him."

They brought him upstairs, put the box on the table and Sherlock stared at the cat. Not sure what he felt about it being in their flat or why he even agreed on helping it back to health. He never understood the company of creatures of any kind. He had a goldfish once, a present from his grandfather. It died during the first experiment. The fish had swum faster and faster in a perfect circle the hotter the water got in the pot, then it died and floated to the surface. Ridiculous animal. Then there was the family dog, Bernard. The oldest dog ever lived, he used to think. Senile and boring, sleeping at all hours except when food was served. Also ridiculous.

He stared at the cat, black as the night it was, eyes golden and piercing him with black, slim slits. Even the whiskers and pads was black, there wasn't a single white hair to be found and Sherlock had to confess that he was quite fascinated of how beautifully this cat was bred. It was like looking at a demon from a horror story. The cat purred by the pain in his twisted back leg and Sherlock stroke his glove-clothed finger over the ear and the creature leaned into the touch, blinked as they always did when they felt gregarious.

"We're gonna help you." Hamish comforted with a calm voice and reached out to touch the bridge between the golden eyes. "Don't worry."

"Get a towel, Hamish." Sherlock asked of him. "And the box of sedatives, we need to calm him if we're gonna do this as painless as possible."

"Maybe we should wait for daddy." Hamish doubted and Sherlock chuckled, they didn't need John for this. This was simple, just a shot and the cat would doze of for couple of hours so could pop the leg back into place, as he said, simple. A child could do it, he'd learnt in online.

"No need, I know what I'm doing." But Hamish shot him a furious look, furrowed his forehead and licked his lips.

"He's not for experiments!" he thundered, suddenly very protective of the cat. "You're gonna kill him."

"Oh shut it, I'm not gonna kill him. Get me a towel and the box of sedatives and needles." Sherlock demanded but Hamish stood and stared at his father to make sure he was telling the truth. He would not let this cat meet his end because the detective saw something fun and interesting in it. He had saved this cat, and he would not be the one leading it to its death because he's asked his father to help.

Sherlock frowned when he looked at his son, it irritated him that Hamish didn't believe him when he was always right. It was just a cat, why was he so worried about it. And besides, it wasn't an experiment if he knew what he was doing.

"Hamish, I promise. I'm not going to kill him. I'm just gonna take some of the pain away so it doesn't hurt when we splint the leg. And also, I can't hold him until daddy get's home and we can't let him go, he will hurt himself even more if he tries to run right now." That was all it took to make Hamish believe him and he backed away slowly before he turned and ran.

Sherlock was left alone with the cat, staring at it as it felt more and more safe in their presence and thought about Hamish's words. How on earth would the sound of his voice calm this creature? But after all that was the exact same thought he had when he saw Hamish for the first time, then five days lated the boy wouldn't stop screaming until he heard his voice. He bowed his head, stared into the yellow eyes and decided to experiment.

"It's going to be fine.. We're gonna pop that leg into place and in a couple of weeks you'll be able to run off again."

"He's not running off." He turned and saw Hamish hurry over the floor with the box in his hands. "He lives here now."

"No he doesn't." Sherlock snorted and pulled the towels out of his hands to swaddle the cat so he could give it the shot.

"No?" Hamish asked and gave him the stare of death. "What are we going to do with him then? We can't just toss him out now, can we? That's cruel!" Sherlock frowned and thought about that for a moment before turning to Hamish.
"Is it?" he asked and the boy's face turned into a expression awfully like one of John's.

"What do you mean!? Of course it is! We can't just throw him out with a broken leg. How is he going to survive? We're keeping him!"

There was no place for a cat in the house, Sherlock thought and groaned. Stared at the demon in front of him with only the head sticking out of the towel.

"You're just like your daddy." he muttered and asked his son to hold the swaddled cat while he loaded a syringe. He jumped up on the table, placed both hands around the skinny creature and held him down. Eyes grew when he saw the big needle and a feeling of doubt appeared again.

"We should call daddy." he said winced when the liquid spurted out of the tip. "You don't know what you're doing." Sherlock groaned irritably and threw back his head.

"Yes I do! I read it on the internet."

"That's what scares me!" Hamish shouted and shoved the box away from him. "Call daddy!"

"Hamish.."

"NO! Call daddy! You're only gonna make it worse!"

"Oh, for christ's sake!" Sherlock snapped, and threw the syringe in the sink with a clink. Argue with Hamish was a bad idea he had come to notice. That boy could twist and turn his words until not even he could understand what they were talking about on a very childish level. With a loud sigh and pulled up his phone and dialled the number. Three signals and someone picked up.
"John, you need to get home."

"What? Did something happened?" the doctor asked worriedly.

"Hamish wont trust me on patching up a broken leg." he groaned angrily and gave his soon a furious stare that the boy just waved away by rolling his eyes.

"WHAT!?" he shouted and Sherlock was rather surprised by his reaction. "What the hell are you doing Sherlock? What happened?" The sound of rattling keys and doors being opened and closed was heard and Sherlock gave him a grunt, not even the doctor believed he could cure a cat.

"I was just going to give him some sedative and he started shouting."

"What the hell Sherlock!" John fumed and his voice was muffled by the sound of cars. "Don't touch any of my supplies, don't try to heal him on your own. Just... hold him, try to comfort him." Sherlock frowned, turned to the cat and stared at the black silky fur. How was he supposed to comfort it?
"Why are you getting so upset?" he asked him, just given the answer of a sigh and the doctor hung up on him.

"Dad..." He looked up at Hamish whose lips were white by his try to suffocate the giggling tickling in his chest. 1. "You do realise he thinks you're talking about me, right?" Sherlock pursed his lips and moved closer to him, saw the cat trying to squirm out of the fabric of the towel. "He thinks it's me who's broken a leg." The detective eyebrows knitted together over his nose.
"Why would he think that?" he asked and put down his phone on the table, peeled a piece of the ham and held it before the eyes of the cat. It devoured it hungrily, growled as it chewed like he was afraid someone would steal it out of his mouth.

"Because you never mentioned anything about a cat." Hamish chuckled and pinched a pice of paté to let the cat lick it of his finger and Sherlock thought about the conversation he and John just had. Shit, he would be hearing this for weeks to come.

"Well, at least he's on his way home so we can put this behind us. Think you can hold him until daddy shows up?"

Still sitting on the table, feeding the cat now and then, Hamish nodded confidently. This was no match for him, the cat was weakened by the lack of food for the many days he'd lived in the bushes and had no energy to fight the grip of Hamish or the towel.

Sherlock observed the situation for a moment and realised that as he and John had predicted, Hamish had inherited the head of the detective but the heart of the doctor. A smile twitched the corners of his lips and he pulled out a chair to join him in the waiting, helped him feed the poor creature in his hands while Hamish cooed to it.

"You know," Sherlock began and and shoved the supplies aside for a moment. "When you were less than a week old, the only thing that would calm your screaming was when you heard me talk."

Hamish looked up under the dark strands of his dark hair and the blue-green eyes turned into a shade that matched the gold of the cat's demon like eyes.

"Really?" he asked with a thin smile and felt the rough surface of the animals tongue work it's way to the palm of his hand. It was craving salt and found it in the crease of the boy's hands, licked it eagerly and purred hungrily.

"Yes, your daddy wanted to threw you out the windows sometimes." he joked and managed to get a giggle out of Hamish who still was a little shaken by the sight of the needle in the hands of the wrong father. "But then we realised that the only time you would sleep was when I held you. I guess you found comfort in my voice." The detective almost got melancholy by the memories and he felt his smile getting more and more crocked as he thought of them.

"Daddy would never throw me out the window." Hamish giggled and got very curious on the subject. "Did I cry a lot?"

"Only always." Sherlock muttered and scratched his head. "But luckily, you were very distracting. You never got boring. There was always something to do with you around."

"Are you saying I'm boring now!?" Hamish exclaimed as he frowned, almost looking worried that he actually was and Sherlock nearly panicked when he saw those thoughts travels his sons head.

"What! No!" he shouted. "Of course not. You're still... distracting, i guess. Just.. in a different way." Hamish eyed his father for a second, giving him a laugh filled of smugness and Sherlock felt his eyebrows disappear into his hairline. "What?" The boy nibbled his bottom lip and turned to the cat again.

"You just.. looked so nervous for a moment." he answered, proud of his success of putting his father in such an awkward situation and Sherlock furrowed. Pursed his lips so he wouldn't slip in a comeback like he did with everyone else that teased him. No, he let Hamish win this round and returned to feeding the cat when they heard the door downstairs.
"Sherlock!?" John shouted with a voice echoing through the house. "Sherlock!?"
"In the kitchen!" he answered calmly and listened to the quick footsteps in the stairs reaching the entrance. The doctor rushed into the kitchen, still in the white robe and heart in his throat as he observed the scene. His face turned from terrified to confused in seconds and he stared at Hamish and the cat as his eyebrows knitted together.

"What..." was all that left his gaping mouth and he took two long steps to get closer to the table. Chest heaving, his shoulders dropped several inches as he started to understand what Sherlock had been talking about on the phone. Both lips was sharply bitten by his teeth as he shot Sherlock a murderous look. "A cat!?"

"Yes, John. A cat." Sherlock sneered when he decided to never agree to that he had done anything wrong and John pinched the bridge of his nose. He let out a big breath with all the fear and worry he'd felt the last couple of minutes.

"And you didn't care to mention that as we spoke?" he fumed and it looked like he tried to pull the face of the bones.

"If you had been more observant, you might have noticed I did." Sherlock tried and John groaned loudly as he pulled the hair by the roots.

"Oh for christ's sake, Sherlock. This might be the day that I decide to put you down." he moaned angrily and arms fell to his sides as he walked over to the chair beside his husband and fell down heavily. "So what happened?" He leaned close to the black cat and stared into the yellow eyes that so frightfully observed the monsters that had kidnapped him.

"Hamish found him outside." Sherlock answered him and John took the poor thing out of Hamish's hands. Unfolded towel and the cat looked to tired to fight the hands.

Sherlock loved to see his husband work and show his medical skills. The cat dozed off in the shoebox as he sedated him and the doctor kept himself quiet during the procedure. Maybe he was concentrated, maybe he was furious or maybe he was afraid that he if opened his mouth he would blurt things out on Sherlock that didn't fit the ears of a child. It didn't matter to any of them tough, because he was healing the cat, popping his leg back into place and splinting it tightly, leaving Hamish with a satisfied smile. He took a deep breath when he was done and looked up at his son.
"There, all done." he muttered. "He will wake up in a couple of hours." Hamish picked up the lips cat and held him like an infant to his chest. "What are we gonna do with him?"

"His name is Boe." the boy said and played with the long tail. "And Boe lives here now."

And that's how the Watson-Holmes family got grew with another member. Because neither Sherlock or John had the heart to say no to the poor animal that Hamish's had saved.

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