Inspired by His Last Vow, and as close to canon as I could make it. Apologies for any purple prose, this has been the work of several 2ams.
The ending wasn't planned, but then again the whole thing wasn't exactly, either... ugh, I don't know, but enjoy!
A roll of thunder, a flash of white lightning. As the room was illuminated, Mycroft gave a thin smile. There was something he loved about storms at night. As the rain picked up, hammering against the window of the cottage with a sound like a car on gravel, he moved the Law book to a side, and took in its place the History one.
History. More who studied History became barristers and lawyers than those who studied Law, somewhat ironically. Not that Mycroft had any interest whatsoever in going into Law. Too easy. A waste, he knew, of his vast intellect. He placed the pen down momentarily, and reached for the bag of toffees at the end of the desk. Just one wouldn't hurt. He reached again, fumbling rather more agitatedly this time. He scanned the top of his desk for the bag. He didn't have to look very far; the bag lay at the very front of the desk, completely empty. Mycroft raised an eyebrow in annoyance. "Sherlock…" he muttered.
The bag fell to the ground as a sudden, especially strong burst of wind whistled through a gap in the frame. Father was supposed to fix that, he remembered. Still. Never mind. He returned his attention to Nicholas II, unable to stop himself from sighing at the Tsar's many mistakes. Just giving in to the urban workers would've worked wonders for his popularity. And if he hadn't gone to war with Japan. No one had wanted to go to war with Japan. This was always the problem when the ninety-nine per cent were given any form of power.
He scanned through the text, searching for anything he didn't know already. A pointless exercise; it was there, all of it, in his mind. Maybe he'd learn Cyrillic. Or… maybe that could wait for another day. As much as he hated to admit it, at 2am he was growing tired, and the thunder had rumbled so loudly he was almost convinced that he could feel it shaking the house. A whimper sounded from downstairs; clearly, the storm had even woken Redbeard, and that dog could sleep through pretty much anything.
Though it wasn't only Redbeard who'd been awoken.
The dog's whimpering was soon followed by a tentative knocking on Mycroft's bedroom door. "Come in," he said, carelessly, loud enough for whoever it was (though he had a strong suspicion as to who), but, he hoped, quiet enough so as not to wake Mummy and Father.
The door creaked open, and Mycroft's little brother stood in his blue pyjamas, thumb in his mouth, and tears glistening on his cheeks. "Mycroft…" he murmured, flinching as a gust of wind rattled the roof slates.
"Sherlock?" Mycroft asked, closing the book in front of him. "What are you doing awake at this time?"
The dark-haired boy didn't reply for a moment, and just stared at his brother, shivering. Eventually, he spoke, though his words, to Mycroft, were unintelligible.
Mycroft sighed. "Sherlock. I cannot understand you with your thumb in your mouth."
Sherlock remained still again, before slowly lowering his arm. "T-the thtorm—storm…" he whispered, correcting his lisp. "I… I don't want—"
He didn't finish his words, as, at that moment, thunder rolled again, and the five-year-old ran straight for his brother's arms, hiding his head in his chest. Clinging to Mycroft's dressing gown, Sherlock looked up. "What's wrong?" Mycroft coaxed, trying his best to disguise the fact that he just wanted to sleep. Sherlock's eyes were fixed, almost as though he were deep in thought. "Sherlock."
He snapped back to reality, and opened and closed his mouth, like a fish. Mycroft's brow furrowed.
"I don't want it to take me away!" the small boy suddenly said, bursting into tears. "I don't want to go!"
What… Mycroft thought, lightly stroking his brother's back. He knew that a great deal of contact could sometimes be too much for Sherlock. Especially on his feet, Mycroft noted, realising that, as was usual whenever he had the chance, his brother was barefoot. A sudden flash of lightning, and Sherlock, with a cry, clung even closer to Mycroft, and the older boy couldn't help himself from holding him tightly. And, unusually, Sherlock didn't seem to object; if anything, Mycroft was almost thinking that he was relaxing…
"What is it, Sherlock? Nothing's going to take you away…" he was confused; from where had he even picked up this concept? It wasn't the sort of thing their parents would catch without a knowing snort of how ridiculous it was, then a softer explanation to Sherlock as to why it was. Not even Mycroft himself would let him believe something like this.
"But…" Sherlock hiccupped, "but you th… you said… you said the East Wind would take me away, Mycroft… I don't want to go away!" full, choking sobs shook his body as he shrunk further into Mycroft.
It was then that a huge, sinking feeling of guilt descended over him. The East Wind.
"One day the East Wind will come to take away all those who are unworthy. That means you, brother mine."
The sly grin he saved especially for that little tale. But he… he hadn't expected Sherlock to believe it! That was just stupid. Whoever had heard of a wind which could remove those who are deemed 'unworthy' from the face of the Earth? Insanity.
"Mycroft, don't scare your brother. You know he can't tell if you're being truthful or not."
Suddenly, what Mummy had said made sense. He'd always wanted to contradict her in the past; of course he knew when he was lying—he was always the first one to point it out. But Mummy hadn't specifically mentioned lies, had she? No. What she meant, Mycroft suddenly realised, much to his horror, was that her youngest son was incapable, sometimes, of distinguishing between fantasy and reality. Especially when the words came from a source which he trusted…
"Sherlock, listen to me," Mycroft said, his voice shaking slightly—he fixed that—as he gently stroked his brother's face. Red, puffy, grey-blue eyes looked up at him, still sparkling. "There is no East Wind, Sherlock, not in that sense. I made it up. It's a story."
Sherlock seemed to be considering this, not quite believing. Or not wanting to. He frowned, quickly rubbing the tears from his face with a tightly-clenched fist, which quickly darted back to Mycroft's dressing gown. "But you said it…" he seemed to be scrutinizing Mycroft's features, trying to understand the unreadable expression crossing his features.
And Mycroft was frozen at the sudden outpouring of raw emotion in his brother's voice. The confusion and, though he loathed to admit it, betrayal. He slowly ran his hand over Sherlock's hair, not knowing exactly how to respond. Sherlock, to whom eye contact was usually an unnecessary evil, would not unlock his eyes from his brother's. Suddenly, the storm seemed irrelevant, as the room was filled with a discomforting silence.
"I'm sorry, Sherlock, I shouldn't have…" Mycroft eventually found himself murmuring. Sherlock made no response, and it was only then that Mycroft realised he was deducing something; what it was, he didn't want to know. Either way, Sherlock seemed to be struggling to make sense of it.
'Liar' was Mycroft's primary idea.
Another roll of thunder, a sound like the firing of a gun. Downstairs, Redbeard gave a short, sharp bark. Sherlock's concentration lost, he whimpered and shut his eyes, and Mycroft held him tightly.
"Mycroft…" Sherlock mumbled, not looking up from Mycroft's body. Usually, Mycroft would reprimand him, but he really didn't feel like doing so, not this time.
He knew what he was about to ask. He smiled. "I suppose so, Sherlock."
Sherlock raised his head, surprised at the lack of persuading required. "Really? Really-really?"
"Really," Mycroft confirmed.
With Sherlock in his arms, he stood, and moved towards the bed in the corner of the room, pulling back the duvet and carefully setting his brother down. As he stepped back to turn out the light, Sherlock reached out, arm outstretched. Mycroft rolled his eyes. "Don't be stupid, I'm not going anywhere."
"Well, you are, you're going over there," Sherlock corrected with a smug grin. Mycroft just sighed, and edged back with only a small line of light streaming in from behind the curtains for guidance. He lay beside Sherlock and covered them both with the duvet. Sherlock curled up, resting his head against Mycroft's chest.