Disclaimer: I do not own Sherlock, clearly. If I did I wouldn't be writing fanfiction - I'd be making it canon. There done.

Author's Notes: Yes, another Mycroft-and-Sherlock-sibling fic. What can I say - their relationship fascinates me because despite the 'arch-enemy' tensions from Sherlock, I can completely see Mycroft being an awesome if not unorthodox big brother to him. Anyway I hope you enjoy this, it hasn't been beta'd.

Monster Hunting for Beginners

"My?"

Sherlock Holmes was four and a half years old. He had wild curls that always had a distinctively windswept look, though that is really because he was always running everywhere. He didn't walk, walking is boring, don't cha know? It's a grown up thing and is so utterly slow and boring. So he runs, runs everywhere, more often than not tripping over his untied laces.

Like tonight: but this time he didn't have any laces to trip over - he didn't even have his slippers on. His feet were cold from hurrying along the cold oak floors to his big brother's room which his parents moved to the East Wing when Mycroft went away to school. He moved quickly, the shadows all about him, his heart racing and breath short. He pushed open Mycroft's door, leapt in and shut it. Watching the door for a second, making sure it really was shut and then he hurried over to Mycroft's bed.

Sherlock didn't like the idea of his big brother being away - though he knew that was what big boys had to do. His father had explained that to him very clearly when Mycroft had started to pack at the start of the week. Mycroft was a big boy and had to go away - Sherlock would also do that when he was big. That didn't make it any better though. Why did Mycroft have to go?

Sherlock didn't like Mycroft not being around. Father was always working, and Mummy was always busy in her lab. It was 'always later' during the day (though at night his Mummy did let him help with dinner and let him stay up and watch television very late). What would he do when Mycroft was gone? Who would he play with? Who would teach him about all the big boy stuff - like how to create an electric circuit and how to make a volcano? Mycroft always knew what to do.

What would he do? Who could be turn to?

Like now.

Sherlock knew Mycroft would know exactly what to do now.

He'd stop the monsters.

"My?"

He asked it again, voice quiet and but precise.

"Mycroft?"

At this his big brother stirred slightly.

"Mycroft - wake up!" he said again, stealing a quick glance around the darkened room and pushing himself onto his brother's bed. His eyes scan the room, taking in the stack of books on the desk, the shadows of the trees creeping through the window and outlined by moonlight, the stillness except for the whistle in the air, and the - his eyes hit the tall wardrobe directly in line with the end of Mycroft's bed.

Sherlock reached out with a tiny hand, shaking his brother on the shoulder, wide eyes on the wardrobe as it stood menacing over him with ornate wood carvings that reached out for him. He bit his lip, applying more pressure as he breath caught.

"My -"

Mycroft's eyes open and he peers at Sherlock. "What?"

He went to sit up, Sherlock adjusting on the bed as Mycroft's long legs move. He turns on the small lamp by his bed, blinks in the light and frowned.

"What is it, Sherlock?" As Mycroft asked he followed the line of his brother's sight, seeing the wardrobe. He sighed. "Sherlock, look at me,"

Sherlock steals a glance at Mycroft, but his eyes spun back to the wardrobe - just in case. He doesn't think there would be any monsters in here - Mycroft is scarier than monsters after all. But you couldn't be sure - Father always said that:

"Watch your back, never think you know everything about a place even if you go there every day"

And so Sherlock kept his eyes on the wardrobe.

"Sherlock - look at me," ordered Mycroft, "Now,"

The smaller boy slowly turns his gaze to Mycroft, wiggling slightly so he can keep one eye on both his brother and the wardrobe.

"Sherlock, there aren't any monsters in the wardrobe," he said calmly.

Sherlock turned to face Mycroft. "Double sure?"

"Double double sure," said Mycroft with a smile.

"Double double double -"

"Yes," and after a pause he said, "There aren't any monsters, Sherlock - they aren't real. They're make-believe,"

"How do you know that?"

"Because," says Mycroft, running his hand through his light brown hair, thoughts dancing in his mind as he contemplates how to deal with his little brother, "So go back to bed, Sherlock,"

Sherlock shook his head. They were real - even Father said so whenever he listened to the radio in the morning and started to talk to Mummy in grown-up talk.

"'Because' isn't a reason," said Sherlock, sticking his bottom lip out, "'Because' means you don't actually know - besides Father says there are - he said it the other day,"

He tilts his head to the side: a challenge.

Mycroft looked at him. He just looked at him. The look said so much more though because it had a hundred different undercurrents sparking off the surface. He squirmed under that gaze. It was the one he got whenever he did something bad, or 'not proper'. It lingered, and surrounded him and he knew looking away wouldn't stop it. It never worked that way. It wasn't something to be ignored. It was scariest than Father because with Father he knew would be sent to his room.

Mycroft couldn't send Sherlock to his room - he knew that. But he could do other things, say other things. Sherlock couldn't predict what his brother could do because Mycroft wasn't like other big brother's.

So he stared back - for a total of ten seconds before glancing at his feet.

"Sherlock those are a different type of monster …"

"How?" he asked, looking back up. "How are they different?"

"Well, they are -" Mycroft shook his head, "Okay - let's go monster hunting,"

"Can't I just stay with -"

"What are you going to do when I go away?"

Sherlock blinks. Question: what would he do? Answer: … he doesn't know because Mycroft won't be there. Mummy is, and so is Father but Father will get grumpy and Mummy will take him to bed, tuck him in and leave him alone. There won't be any words, there won't be anything.

Reason: Mycroft is gone.

What could he do?

Mycroft watched his little brother tease it up and when he glanced directly at him, said. "Monster hunting it is then,"

He started to get out of bed, and so Sherlock moved quickly off, grimacing at the cold floor. Mycroft came around and took one glance at his face and looked down, shaking his head. He went over to his drawer, and Sherlock's eyebrows crinkled as he wondered what he was grabbing? A secret weapon that would destroy the monsters? Something only big boys got? Was it a - he leaned forward slightly, eyes like dinner plates.

Mycroft turned back, holding some socks.

"Okay, rule one: wear your slippers,"

"Why?"

"Monsters can't get your toes then," said Mycroft.

Sherlock swallowed, looking down at his feet and making sure all the digits were there.

They were - phew.

"Socks will do for now," said Mycroft, handing them to his little brother. Sherlock immediately set to putting them on and Mycroft continued. "Why do you think Mummy always tells you to wear your slippers?"

"Oh,"

"Yes," said Mycroft, giving Sherlock a wink, "Monsters don't like big toes - they like lots of little ones,"

"So they think it's just one big toe?"

"Yes,"

Sherlock catalogued that away for future monster hunting.

"Now second rule: torch - monsters hate light - that's why they hide in the shadows," Mycroft grabbed his torch. "When you put the light on them it reveals the truth,"

"Is that all, My?"

"Yes,"

"No weapons?"

"Sherlock - we aren't apes. Gentlemen fight monsters with their brains - not with brute strength,"

Sherlock frowned. "Gemtell -"

"Gentlemen," clarified Mycroft, pronouncing it slowly. When he was done, Sherlock repeated it back and Mycroft nodded, satisfied. That was the rule with Mycroft: if you couldn't say a word, you had to keep repeating it until you got it right. That was the rule.

"So monster hunting?"

"The game is afoot, yes," said Mycroft.

He took Sherlock's hand, who clenched it tightly and soon the two brothers were out of Mycroft's room and creeping along the lonely corridors of the Holmes Manor. Old paintings of their ancestors watched them, eyes seemingly unmoving from their rigid positions. Sherlock stepped in closer to Mycroft, trying to keep with his longer strides.

They reached Sherlock's bedroom, and Mycroft went in first, Sherlock following close behind him. The door snapped close behind them.

"Should we turn on the light?"

Mycroft shook his head, passing the torch to Sherlock. "Now, where would a monster hide?"

"The wardrobe?"

"Where else?"

"Under the bed?"

"Where else?"

"The curtains?"

Mycroft gave a small nod. "Anywhere else?"

"The toy box?"

"Yes - now let's go have a look,"

They went around Sherlock's room, checking each spot - or rather Mycroft watched while Sherlock checked. He held the torch straight out in front of him, like a sword, his whole body tense and ready to run. Just in case. He was quick, looking at every inch of the wardrobe, pulling the curtains back so the moon bathed them, digging through the toy box (after much insistence from Mycroft - he really didn't want to stick his hand there in case a monster bit him), and glancing under his bed.

He couldn't find any. But they had been there - he had heard them! He turned to Mycroft - had they moved around? Where they somewhere else? Could they teleport? Did they use the shadows to move in a single blink of -

"Why do they hide there?" asked Mycroft. "Sherlock - why?"

Sherlock bit his lip, mulling it over. Where did they hide? Dark places, enclosed places, places with openings - opening to the monster world - why did they hide there? Because they were hidden there.

"Because they can hide there?"

Mycroft sighed. "Think it through,"

"I did,"

"No, you didn't,"

"Did so,"

Mycroft sighed, and bent down to Sherlock's height. He placed his fingers on Sherlock's temples looking straight into his eyes.

"Why do people hide?"

"Because they don't want to be found … because they are …" then it hit him. Came rushing at him as his mind connected the dots, a spider web forming, "scared - the monsters are scared …" he blinked "of us?"

Sherlock cocked his head to the side. "That doesn't make sense,"

"Of course it does," said Mycroft, "Because we know why they do things - they can't fool us, we're monster hunters, you and me, Sherlock - monsters fear those who can bring them to justice because they know if they do misbehave we'll get them - they wouldn't dare because you know all about them - that is scary,"

"Double sure?"

"Double double sure,"

"Double double doub -"

"Sherlock, enough," said Mycroft, sending him a dissapproving look.

"Sorry,"

His features softened. "Anyway, of course I am sure,"

Sherlock wasn't completely sure with Mycroft's logic but Mycroft had said it - and he was already right. Mycroft always knew what was really going on, and always had an answer. That's why he was Sherlock's big brother. So he had to be right, and it wasn't like he would ever lie to Sherlock either and so logically everything Mycroft said was the truth.

"Okay," nodded Sherlock.

"Yes - now go to bed and in the morning come find me - if all your toes are still attached you'll know I'm right,"

When Sherlock woke up the next morning, after Mycroft put him to bed and left him ('if I stay then they'll know you aren't a real monster hunter, Sherlock'), he counted his toes.

They were all there.

He smiled and went to find Mycroft.

Fin

Author's Notes: Thoughts are very much appreciated.