Hi everyone, this is my first fanfic here on the site, and I hope you enjoy it!

Please review, as I would like to improve my writing.

Oh, and Sherlock doesn't belong to me, he belongs to ACD and the BBC.

It was an abnormally hot day in August, and all twelve year old Mycroft wanted to do was take a cold shower while reading a book, all this ideally while lying down. Instead, his parents had to go out and he was stuck babysitting the loud, hyperactive, impulsive five year old menace known as Sherlock. The young Holmes was outside in the scorching sun, doing something that Mycroft really hoped was harmless. Unwilling to go anywhere near his garden and actively babysit, Mycroft was lying on the couch in his living room with a huge book about the history of British politics, idly flipping through the pages. He had started the day wearing his favourite tailored suit and tie, but by this time in the late morning he had been reduced to wearing shorts and a sleeveless shirt, and he was actually considering taking off the latter. He was trying to concentrate on his reading, but something was bothering him. At first he thought it must be the heat, but after a few minutes he realized that the thing causing him unease was how quiet it was. Usually babysitting Sherlock meant hours and hours of "Mycoff, I'm BOOOOORED!" (The boy was almost five, but hadn't really gotten the hang of his brother's name yet). Perhaps he should go check that his brother hadn't died of heatstroke or dehydration, or been run over by a car, or set fire to their family cat for the second time this month. Then again, it was so hot outside. If Sherlock was dead, Mycroft could not help him by running outside in the sun. The boy ran his fingers through his sweaty auburn hair to get it out of his eyes and continued reading.

'If Sherlock is dead,' He thought, 'I might as well have one more day of normalcy before becoming mentally scarred forever.' Suddenly, he heard the front door open and close, and a fast and faint patter of feet coming from the door and down the hall. Then he saw a small blue blur running down the corridor past the living room and to the kitchen. Then the real noise started. Mycroft heard the clang of pans and cutlery hitting other pans or cutlery, some drawers opening and closing, and cupboards being opened and slammed back shut. Then he saw the same blue blur running back, this time with a worryingly big knife in hands.

'I should get up,' Mycroft told himself, turning another page, 'I should honestly get up now,' But the English civil war was very interesting.

'Mycroft Holmes, get up this instant,' a small, nagging voice in his head said.

'But it's really hot.'

'Mummy will kill you if Sherlock does something bad with that knife.'

'But it's really hot. Sherlock might not be doing something bad.'

'How likely is that?'

'Not very.' This was Sherlock Holmes after all. Only this summer, the boy had almost burned the house down five times, tested random drugs from the medicine cabinet on the cat (The Holmes' family cat was a long suffering one indeed), tested random drugs from the medicine cabinet on himself, tried to chop down the massive tree in the garden with an axe to see if he could accurately predict where it would fall (He was wrong. It ended up falling on Mycroft's leg after the older boy pushed him out of the way. It took an hour to get the blasted thing off him, followed by five weeks with a cast on his very badly fractured tibia), and attempted to rappel off the roof using a rope made of Mycroft's ties, not to mention the incident with the giant rat… Yes, if Sherlock had a big knife, the situation probably required his immediate attention and intervention.

"Sherlock?" Mycroft cried out. He hadn't heard the door open and close yet, so Sherlock was still in the house. Nevertheless, he got no response. He listened hard for the sounds of Sherlock doing something horrible, but could not hear anything. There was no choice. With an annoyed huff, the boy placed his massive book on the floor, got up from the sofa and walked to the entrance hall. What he saw there almost made him jump (almost, because Mycroft was not the jumping type).

"Sherlock, what on earth are you doing?" The boy was sitting in a small pool of blood, the knife in his hand and the remains of what appeared to be a raven on the floor before him. The boy was hacking away at one of the wings, an expression of intense concentration etched upon his features.

"SHERLOCK!" Mycroft shouted again.

"Whadoyoo want?" Sherlock replied angrily. His blue eyes were riveted on Mycroft's knees (which were in front of his face), and he looked absolutely furious.

"What. Are. You. Doing?" Mycroft accentuated every syllable.

"Conducting post-mortem," Sherlock answered simply, then returned to mutilating the crow. Mycroft rolled his eyes. Despite being almost five years old, Sherlock hardly had the communication abilities of someone two years younger than him. This often clashed with the fact that he had the mental capacity of someone twice his age. The boy was incapable of making eye contact or answering questions like "How are you?" but fully capable of understanding what "post-mortem" was. His parents suspected that he might have mild autism. Mycroft did not know if they were right, or rather that Sherlock chose not to interact with others because he found it boring.

"Well, what do you think mummy will say if she sees you conducting post mortem on the floor of our entrance hall?" Mycroft asked sarcastically.

"Dunno." Sherlock pushed his overgrown black curls out of his eyes, smearing his forehead with raven-blood in the process. Mycroft's hair was always trimmed to perfection, but Sherlock would start shrieking every time someone approached him with scissors, so he hadn't had a haircut in some time.

"You don't know? Sherlock, mummy gets squeamish every time someone kills a fly next to her! She'll lose it if she sees this!" No response.

"Sherlock, stop!"

Sherlock had removed the wing, and was now studying it with a magnifying glass that he always kept in his pocket. There was no trace of emotion on his face. The fact that he was covered in blood and touching a mangled carcass did not trouble him in the slightest. Mycroft reached for the knife, but the second he touched it his brother started screaming at the top of his voice while jerking the knife away from him.

"NO DON'T NOOOOO!" Mycroft let go. If Sherlock decided to throw a fit with a knife in his hand both of them could get badly hurt. Mycroft sighed. He knew this could not continue, but how was he going to stop his brother without getting stabbed?

"Sherlock, did you kill the bird?" Mycroft asked quietly. It was not likely, but again, this was Sherlock and Mycroft had learnt never to underestimate him.

"No," Sherlock muttered. He was pulling at the black feathers now, studying both them and the skin under them intently.

"You can't just pick up a corpse and bring it in!" Mycroft cried. He had to get the cadaver out of the house before his parents returned. Perhaps reasoning with his brother would work. "It might be infected with something! It could have died of avian flu! This is really, really dangerous, and you should get this thing out of the house, wash your hands really thoroughly and use your brain next t-"

"Mycoff?" Sherlock suddenly asked. Had he listened to anything his brother just said? Probably not. Mycroft rolled his eyes.

"What is it, Sherlock?"

"What's this?" Sherlock had moved from the wing to the body, and was pointing to something inside the bird's chest. Mycroft took a quick look.

"That's a lung."

"Whaddosit do?" The boy asked and cut the small organ out of the body, inspecting it with his magnifying glass and laying it carefully on the floor away from the pool of blood.

"That's how to bird breathes. The air the bird inhales goes into the lungs and the lungs oxygenate the blood." Why was he answering science questions when he should be disinfecting his brother?

"Lungs? More than one?" Mycroft kneeled down next to his brother and gently took the knife from him. The younger boy did not object this time. Mycroft held the bird steady on its back with one hand (with his handkerchief wrapped around it) while cutting it open the whole way with the other. He pointed at the other lung with the knife.

"Yes, there's two. See?" Sherlock nodded, listening to Mycroft with rapt attention, "The air travels through the trachea, here," Mycroft pointed at the bird's windpipe, "And half of it goes to the lungs, and half of it goes to these air sacks, here." Mycroft pointed at the bird's posterior air sack.

"And what's that?" Sherlock picked up the lung from before and pointed at the air sacks attached to it.

"These are also air sacks, they're used to ensure that the air inside the lung flows in one direction only."

"Do I have air sacks?" Sherlock asked, taking back the knife from Mycroft and cutting out the other lung. The younger boy held them both up to the light, comparing them.

"No, they are unique to birds."

"And what's that?" Sherlock asked curiously, pointing to another tube with the knife. Mycroft was shocked. He hardly recognized his brother. Sherlock was sitting quietly, making eye contact, and constructing whole sentences. He seemed almost calm, almost talkative. Almost normal, if you could look past the fact that he was covered in raven blood and holding a very big knife. Mycroft knew that he should get the bloody bird out of the house, throw away the knife, and disinfect everything, but the change that had suddenly come over his brother was fascinating. And anyway, what's a little avian flu when your semi-autistic brother was finally talking to you?

"That's the oesophagus."

"Oh! I know what that does!" Sherlock said with a proud grin. One time Sherlock almost choked on a grape when he tried to see if he could breathe fruit. After that their mother refused to let Sherlock have anything to eat before he recited "Food goes in the oesophagus and absolutely nowhere else" about one hundred times to her.

"You would know, yes…" Mycroft said with a smile. They dissected the bird for an hour. Sherlock's eyes were wide with wonder as he listened to his brother talk about the various organs, how they connected to other organs, and whether or not Sherlock had them too ("No, Sherlock, you don't have a gizzard." "Awwwww!"). Finally, after going over every single bit of tissue that could be found in the poor raven, Sherlock said.

"Mycoff?"

"Yes, Sherlock?"

"The raven didn't just die. The cat killed it and I brought it in. You're not going to catch avian flu, so don't worry." Mycroft stared open mouthed at his brother. Sherlock had never said more than six consecutive words in his life. This was an unprecedented event. He decided not to make a fuss of it.

"Oh, I see. That's good. We still have to wash our hands though, alright?"

"Alright," Sherlock replied, rubbing his fingers together and inspecting the blood on them, some of which had already turned brown from contact with the air. Mycroft touched him on the shoulder to make sure he was listening.

"Help me clean this mess up now."

"Okay." Mycroft sent his brother to get a rubbish bag and some wet paper towels, and ten minutes later the floor was clean and the corpse of the raven (now mutilated beyond recognition), Mycroft's handkerchief, and the large knife were in the large rubbish bin at the end of their street. Mycroft told his brother to take a shower, and Sherlock, despite sulking and throwing his brother nasty looks, complied. Mycroft returned to his sofa and his book, and although he tried to concentrate on a fascinating passage about King James II, he couldn't. He was too preoccupied with his brother's behaviour. Seeing Sherlock so happy and attentive had done something weird to Mycroft's brotherly instincts. He really wanted to see his little brother this happy again. He wanted to see him talk and smile, but surely, they could not conduct autopsies in the living room every day just because it improved Sherlock's social skills?

The shower door opened and Sherlock emerged from it wearing fresh clothes. Mycroft followed his brother with his eyes as the boy ignored him completely and climbed to the top of the highest bookshelf in the room. He lay on it, staring at the ceiling quietly and occasionally moving his finger along one of the cracks in the wall or humming to himself. Mycroft knew that if he tried to talk to him now he would either be ignored or snapped at.

Everything was back to normal, then.

That evening, Mycroft took some heavy books on anatomy and biology from his shelf and placed them on Sherlock's bed, together with a note saying "Come to me if you have any questions". He didn't know if it would help. He had no clue if studying these things would improve Sherlock's condition or just turn him into more of an outcast and a weirdo, but he was willing to try. If this turned out to be the one thing that made Sherlock happy, Mycroft was willing to dissect every dead thing that turned up in their garden in the future.

The End.

I hope you enjoyed that! If you did, please review, and if you didn't, please review as well, as I am aware that my writing is not perfect and I would love to get some constructive criticism! If I have grammar errors, PLEASE correct me, because English is not my first language (part of the reason why I'm writing is to improve it!).

Oh, and why does Mycroft know so much about bird anatomy?
Because he's Mycroft, and he knows everything.