Author's Note: This fanfic is something that I've been meaning to write for a while. It may be a pretty obscure and strange mega-crossover but I think it'll turn out alright. I'll be uploading the remaining chapters once I'm finished writing the story. I hope you all enjoy my first fanfic and I plan to write more in the future once I'm done with this one. I should also note that this story not only features characters from Artemis Fowl and Harry Potter but also features characters from My Little Pony: Friendship is Magic, Spider-Man, Teenage Mutant Ninja Turtles (2003 Series), Kung Fu Panda, Sonic X, and Teen Titans. Lastly, I'd like to note that I do not own any of the unoriginal characters used in this fanfic and all rights go to the respective writers, television companies, and movie companies.

The League of Inter-Dimensional Heroes

Chapter 1: The Opal Obsession

It was a quiet evening at Fowl Manor and Artemis Fowl was restless. It had been weeks since he had heard back from anyone else in the League. Their scheduled meeting that month had been canceled and Artemis did not like this. He needed to inform the others about the current situation in his world. Though his arch-nemesis, Opal Koboi, was still locked away in her prison cell down in Atlantis her past self was still running amok somewhere on the planet. However, though her current situation was a mystery, she was a very busy pixie and had been causing problems for the LEP and Artemis for well over a year now. Pixie riots, strange explosions, and mysterious disappearances. Artemis and his allies all knew that this was the work of Opal Koboi, but what was her plan? Since her arrival in the present, she hadn't tried to launch a full-scale attack on Artemis or try to wipe them out one-by-one. She had simply been hiding. Causing occasional setbacks for the LEP. Almost in a prank-like manner. Artemis assumed that these casual pranks were merely distractions in order to cause them to ignore her bigger, and more diabolical plan. But what could it be?

Artemis was busy pacing in his study. He had been doing this every day for a while now. His normally smooth black hair was strewn and messy and his blue eye was clouded and bloodshot. His hazel eye, however, remained calm and normal. Whenever Artemis looked into the mirror and gazed upon his hazel eye he saw and thought of no one but Holly Short, his close elf friend and highly talented captain of the LEP. He wanted to see her so badly, for they had not talked for some time, but he didn't want her to see him the way he was now. This was not the Artemis Fowl he wanted to show her. Artemis stopped his pacing and looked into the mirror again. He tried to comb his messy black hair with his hands but the defiant hairs refused to move back into their original neat state.

"Haven't felt this nervous and paranoid since I had Atlantis Complex," said Artemis as he gave up in trying to tame the bent strands. He took another look at his reflection in the mirror and let out a hearty laugh. "Come to think of it, I kind of look like Harry a bit."

He looked at his reflection for a few more minutes before turning away. She was up to something. He knew it. They all knew it. Opal is just waiting for the perfect moment to strike. If only he was one step ahead like he normally was. Artemis, now growing tired of his constant pacing, walked over to his desk and sat down in the leather chair.

"If Opal's trying to win by driving me insane then she's going to succeed," breathed Artemis as he reached for a glass of iced tea that he had sitting next to his laptop.

A knock emanated from the nearby door and Artemis said, "Come in." The door opened and in walked his loyal bodyguard and old friend, Domovoi Butler.

"Artemis. Twilight's here to see you," he informed.

Artemis quickly sat up and tried to comb his hair again, but it was to no avail.

"Just let her in."

"Okay. I'll just leave you two to discuss business."

Butler then stepped out of the doorway and in walked a lavender unicorn pony with a flowing purple mane and a star-based marking on both sides of her flank.

"Hello, Artemis," said Twilight Sparkle.

"Twilight, please have a seat," Artemis replied as he gestured to a leather chair opposite to him and the desk. Twilight walked over to the chair and awkwardly tried to sit comfortably in it.

"These human chairs! I prefer the cushions back in Equestria," she complained as she finally found her comfortable position. It was at this moment that she saw the state that Artemis was in and couldn't help but giggle teasingly. "Well this is certainly a new look for you, Mr. Fowl. Are you trying to take after Harry in hair styles?"

"Oh shut up. Unlike you, my little pony, I've been really busy of late. Opal Koboi's distractions are becoming more frequent and I believe that it's all leading up to something. Then, to top everything off, you and the others decide to go and cancel our monthly meeting. I thought we all went over this to a T when the League was formed!" snapped Artemis.

"I know, Artemis. I'm sorry but...things came up."

"Well I'd like to hear about these things because I've heard next to nothing from any of you."

"I'm here now. Does that at least make you feel a little bit better?"

"Somewhat. Sorry that I've been so abrupt with you. As you can tell, things haven't really been so easy for me lately. The whole Opal crisis has really taken a toll on me both physically and mentally. But, to be honest, I'm glad that you were the one to see me in this state rather than Holly."

"How long has it been since you've seen Holly?"

"Several weeks. The People have been almost as quiet as you guys. Opal's little distractions have been the most notable occurrences happening recently. Anyway, so what's happening in Equestria?"

"There's been a threat made against Canterlot."

"Again? I swear, that capital of yours gets threatened more than me...and that's saying a lot."

"I know. The Princess thinks it could be Chrysalis again but there's no evidence to prove so. We've scanned the entire capital for Changelings but, like I said, we've come up with nothing."

"So your situation is basically the same as mine. You know there's a threat but there's nothing really serious happening at the current moment to cause you to take drastic and immediate action."

"Correct."

"How are your friends doing?"

"Huh?"

"How are your friends doing? I mean Applejack, Rainbow Dash, Pinkie Pie, Fluttershy, Rarity, and Spike. How are they doing?"

"Why would you want to know that?"

"Well you are my friend, Twilight, and they are my friends too. I'm just curious about how their situation is."

"To be honest, I haven't seen or talked to them in a little while. I've been so busy helping Princess Celestia and Luna in Canterlot that I haven't found any time to go to Ponyville and see them. I was lucky enough to gain some free time today to come and see you, Artemis."

"Oh...sorry."

"It's alright."

Twilight's head fell down and Artemis instantly felt guiltier about being so blunt with her. He had a lot of respect for the magical pony. She was intelligent, organized, fun to be around, and she was the only female in the League. Artemis took these few seconds of awkward silence to try and comb his hair again but he failed once again.

"Where's that comb?" he asked as he began rummaging his hands through the various papers and objects on his desk.

"What was that?" asked Twilight.

"Oh...oh nothing. I was just searching for a comb."

"Trying to fix that mess, huh? No problem."

A purple aura appeared around Twilight's horn and Artemis felt his messy hair instantly revert back into its normally neat state. He brushed his hands through it and was thankful that Twilight had been extra generous and had used her magic to clean his hair too.

"Thanks," he said with a slight tinge of embarrassment.

"No problem."

"Anyway, getting back to business, have you at least heard from any of the others?"

"Sadly, no."

"No one? Harry? Leonardo? Peter? You must have at least heard something from Robin!"

"Sorry, Artemis. None of the others have contacted me. The last time there was any type of contact between any of us was when I sent out my letter to you stating that I couldn't attend the meeting."

"My guess is that similar stuff is happening in their worlds too."

"I'm mostly curious about what's been happening to Harry."

"Why?"

"Well...it's been almost two years since he defeated Voldemort so you have to wonder about who else has taken his place as a new threat to the wizarding world."

"You do have a good point there, Twilight. We should try and contact him."

"Maybe we could visit him right now."

"Do you have any more time to do so? You just said earlier that you were lucky enough to gain some free time to see me."

"I can probably squeeze in another half hour. I highly doubt that Canterlot's going to fall in that time span."

"Okay then. Let's go see Harry."

Artemis stood up and walked over to a door to his right. This door led into a simple closet but, in a few seconds, it would lead into a completely different world. Artemis reached into his left pocket and pulled out a golden key. Even in the dim light of the study, it gleamed as if it were in the middle of an open field on a sunny day.

"I could just use mine," said Twilight as she followed Artemis over to the door.

"Don't worry about it. Besides, it's been a while since I've used my key," replied Artemis with a somewhat playful tone. Artemis then slid the golden key into the lock and turned it. He pulled the key out of the lock and pushed lightly against the door. "Mares first."

The teenage genius smiled mockingly as he stepped aside.

"Shut up, Master Fowl," Twilight chuckled. Twilight kicked Artemis playfully with her front hoof and then proceeded through the portal. Artemis then followed suit and closed the door.