A/N: Oh my gosh, we didn't expect a lot of positive feedback! Thank you all so much!

We don't have any claim Sherlock, Artemis Fowl, nor the blog on which this headcanon was found. Also, apologies for not knowing how exactly the British school/grade system works- we tried to work around that, but if we got anything abysmally wrong, please tell us.

Now for the long-awaited Chapter Two!

Over Hill and Under Hill

The first sign was Sherlock's uncharicteristic silence on the way home from school.

Mycroft, several grades ahead of him, had to walk him home every day, much to his younger brother's displeasure. Today, however, Sherlock didn't say a word, even when questioned about the impish glint in his eyes. Mycroft's suspicions were roused, but he concentrated on getting his brother back home before the clouds overhead released more than the droplets that hit the pair now.

When they got home, Sherlock greeted their mother, then ran off up the stairs to his room.

"Where are you going?" Mycroft asked.

"To do my homework," was the reply.

Mycroft raised his eyebrows. "I thought you said your homework was 'dull and tedious'?"

His brother shrugged. "So's detention."

"Fair point," Mycroft admitted as his brother left.

"At least he's doing it," Mrs. Holmes shook her head, a weary smile on her face. "It will keep him occupied for a little while. Maybe he won't give you too much trouble."

And maybe Angeline's fairy tales are real, too,* Mycroft thought cynically. Aloud he said "We'll be fine. Where is Angeline, anyway?"

His mother smiled. "Using the dining room table as a hobbit-hole." she sighed. "I hate to leave you."

"It's only one night," Mycroft replyed. "Grandmother's sick. You have to go."

"Alright," she nodded, "Angeline already ate. There's Shepherd's Pie** on the table. If Sherlock's not hungry make him eat anyway. Your father should be home before bedtime." she hugged her eldest. "Bye!"

"Bye, Mum," Mycroft returned the hug.

"Bye, Angeline!" Mrs. Holmes called.

"Wait!" Mycroft's five-year-old sister raced into the hall, leaping into their mother's arms. "Gotta hug you first."

Mrs. Holmes gently placed Angeline back on the floor. "You listen to your brother, okay?"

"Okay," Angeline replied.

"I'll be home soon, love," she promised. She turned to the stairs and called, "Goodbye, Sherlock!"

"Have a safe trip!" Sherlock yelled from his room.

"Mycroft's in charge!" Mrs. Holmes added.

"Conditionally?" Sherlock asked hopefully.

"No. Rigidly," their mother answered. She gave her daughter one last kiss goodbye, told them to be good, donned her raincoat, then headed out.

"So, what do you want to do?" Mycroft asked, turning to his sister.

"S'not time for an adventure yet," Angeline informed him, "Come back Wednesday."

"Okay," he played along. "How long is that?"

"Seventeen minutes," Angeline said before skipping back to the dining room.

Mycroft set his backpack down beside his desk. He pulled out his math homework and gave it a quick skim. Of course, like always, it was ridiculusly easy, but, as he always told Sherlock to do, he decided to show his work anyway. He reached into his front backpack pocket to pull out his protractor... which wasn't there. He searched through his other pockets, to no avail. It must have fallen out on the walk. He slammed his book shut and went down the stairs, where Sherlock was exasperatingly trying to explain something to Angeline, who just giggled and muttered "Burrahobbit" to herself repeatedly.

"Are there any protractors in the house?" Mycroft asked his younger siblings.

In response, Sherlock pointed out the window and Angeline giggled harder.

"I'd offer you mine, but it's a liquid now." Sherlock shrugged.

"Oh." Mycroft decided not to ask. "I'll go see if mine is anywhere near the house. You two stay inside."

"Leaving the house?" Sherlock asked with a smirk. "Not very responsible, is it?"

"Gandalf does what he pleases." Mycroft retorted and stepped onto the porch, closing the door behind him.

The first thing he noticed were dark stormclouds circling the sky; it was going to rain hard, and soon. The second thing Mycroft noticed was his protractor lying on the deck, as if placed there, which would explain why Mycroft hadn't heard it fall out.

The third thing he noticed was the click of the lock behind him.

Mycroft whirled around and banged on the door. "Sherlock! Let me in!"

In response, the younger Holmes brother stood at the nearest window and made faces at the thoroughly annoyed Mycroft.

"William Sherlock Scott Holmes!" Mycroft shouted. "You let me in right now! It's going to rain!"

All Mycroft got was an umbrella squeezed through the mail slot and more faces from the window. Once he began picking the lock, however, something thumped against the window from the inside. Mycroft looked, and witnessed Sherlock pummel the window with yet another muffin.***

"Where did you get those?" Mycroft inquired confusedly.

"Mummy told me to eat Aunt Marci's muffins last Christmas." Sherlock informed his brother through the window. "I didn't. I snuck them into my bag and saved them for just such an occasion. You'll find that they're rock-hard."

"You've been saving those since Christmas?"

"They were horrid anyway."

Mycroft was about to say something, but Sherlock then threw another muffin at the window. "I have twenty-nine of these and I'm not going to waste one!" he announced. "Where do we keep the spray paint?"

"Don't!" Mycroft yelled.

"You're no fun." Sherlock sulked.

The ten minutes outside the locked door felt like an eternity. Mycroft was just considering asking to use the neighbor's phone to call his mother when his brother opened the door.

Sherlock leaned his head out and smiled innocently. "You can come in now."

Mycroft snorted.

"And I know what you're going to say," he added. "I know I'm in deep trouble, but come inside now. Angeline and I have a little game to play."

Mycroft glared, but took the advantage of the chance to get out of the rain, which was pouring now.

"And you're welcome for the umbrella," Sherlock snapped, holding the door open for his elder brother.

"You shouldn't have locked me out in the first place!" Mycroft closed the door forcefully. "Sherlock Holmes, Mummy's going to ground you for a month!"

"Oh probably two," Sherlock was still smiling. "Come on, up to your room you go."

"But-" Mycroft protested as his brother shoved him up the stairs.

He discovered why his brother was so anxious to get him to his room when he saw his desk, abnormally bare of papers.

"SHERLOCK!"

* I'm sorry. I'm so so sorry. That was shameful. But I do not regret it. I'm keeping it in there. - NP

** One of the most awkward questions ever is "what do they eat in England?" My knowledge of British culture comes from Harry Potter, Doctor Who and Sherlock. It was this or fish fingers and custard. - NP

*** Do you know how awesome it is to come back into the room to find your writing partner smile and say "Can Sherlock throw muffins at the window?" - NP / Do you know how awesome it is when your writing partner says yes to that? - N8 / I bet Moffat and Gatiss do. - NP

A/N: This chapter was more fleshed-out than the first one, so we split it in two. The next chapter will be posted before the school year stars for us—meaning we've got until September 2— we won't leave you on a cliffie for too long! Reviews are appreciated!