Full Author's Note at bottom.
SPOILER WARNING: Do not read this story if you have not read up through book 7 of Artemis Fowl. This story takes place soon after book 6, but there's major plot spoilers for book 7. Do not read unless you've at least finished Season 1 of Gravity Falls, but this contains major spoilers for Season 2, Episode 12, plus there's a few details that won't make sense unless you've seen Season 2, Episode 15.
I don't own anything except this idea.
Cipher Complex
Bill Cipher was bored. His favorite pawn, Ford, was trapped in a completely useless dimension, and had been for about 25 years. Ford's brother, Stan, wasn't making any progress on opening the portal. Bill could see glimpses of the future, and he knew that things would start falling into place soon, but not just yet. In the meantime, he needed someone to play around with. He'd already had all levels of fun in many dimensions, and he had a lot of playthings lined up in various dimensions to come back to; however, he wanted someone new today. He looked into a few dimensions before settling on 55\EC. "NOW, WHERE'S THE WEAK SPOT?" he wondered. It was easiest for him to mess with minds near a natural dimensional weak spot. He was positively thrilled to find a full-on rift. "THIS IS PERFECT!" he exclaimed, waltzing through the black-magic rift and into 55\EC. He immediately saw a very large manor sprawled out in front of him. "RICH PEOPLE WITH OLD MONEY? HAHA, THIS WILL BE FUN! ALL I NEED IS A GENIUS TO TORTURE AND THIS WOULD BE THE PERFECT SPOT!" Bill floated into the house and examined the sleeping residents. A husband and wife were sleeping together. Bill popped into their memories and saw that they had a pretty happy life and marriage, though they were haunted by past mistakes. "WELL, THAT COULD BE FUN, BUT WHAT ARE MY OTHER OPTIONS?" Bill thought. He floated over and found two little children. "TWINS," Bill thought with utter contempt. "I COULD MESS WITH THEM, BUT THEY'RE ONLY TWO YEARS OLD. JUST NOT AS MUCH FUN." He moved along and found a large buff guy. "OOH, GOLD MINE! BAD MEMORIES, SUPERNATURAL EXPERIENCES, SECRETS, GUILT, THE WHOLE NINE YARDS!" Bill exclaimed, his eye open wide with excitement. Just before he started playing, though, he remembered that there was one more life sign in the house. He decided to spare a quick glance at the sixth person. It was a pale teenage boy who looked like he was distressed. "OOH, A NIGHTMARE? I WANT IN!" Bill exclaimed. With a laugh, he jumped right in to the boy's mind.
5... 5... 4 4 4 4... 20 20 20 20 20... 55555 55555 55555 55555 55555...
Bill watched the pattern of numbers with amusement. They were always fives, fours, or twenties. The boy's mind seemed to hate the fours and love the fives, keeping the twenties as a mediator. "HMMM THIS IS INTERESTING." Bill said out loud to Artemis's mindscape, though he knew the boy's consciousness couldn't hear him. He poked into the boy's memories. Artemis Fowl II, 14 years old, though he's supposed to be 18. Bill prodded further and found that this was because little Artemis had been removed from his dimension for about half an hour, but over three years went by in his own world. Artemis was now a friend of the People. ("UGH, THOSE MEDDLESOME FAIRIES," Bill thought. "NOW I REMEMBER WHY I HAVEN'T BEEN TO THIS DIMENSION FOR A WHILE.") Apparently, Artemis had used to consider the People his enemies, but they were allies now. "HAHA THERE'S A LOVE CONNECTION THERE TOO!" Bill said triumphantly as he stumbled across Artemis's feelings for Holly. "IT'S LIKE REVERSE STOCKHOLM SYNDROME! THIS IS TOO GOOD!" Bill meandered through Artemis's intellect, seeing that he was rather a genius, but that his brain was becoming fried by this number sickness. "YOU THINK YOU'RE JUST CRAZY, BUT YOU'RE ACTUALLY DEVELOPING INTER-DIMENSIONAL BRAIN CONNECTIONS THAT YOU AREN'T SUPPOSED TO HAVE. YOU LOVE 5 BECAUSE 55 IS THE NUMBER OF YOUR DIMENSION. YOU HATE 4 BECAUSE 44 IS THE DIMENSION NUMBER OF THE NIGHTMARE REALM. OH YOU ARE SMART, ARTEMIS FOWL. YOU'RE JUST TOO SMART FOR YOUR OWN MIND TO HANDLE. THAT MAGIC PUT YOU OVER THE EDGE." He laughed. "WELL, I'M GOING TO USE THIS TO HAVE SOME FUN." He poked at the boy's memories and found a few from age 10 that were artificially suppressed. "SOMEONE MIND-WIPED YOU, KID," he commented. He saw that Artemis was actually aware of this. Following the strands of memory, Bill found the time-travel jaunt Artemis had come back from fairly recently… plus all of the other memories associated with that little adventure. "LYING TO THE GIRL YOU LOVE? OH, NO WONDER YOU FEEL SO GUILTY! ALONG WITH THE STRESS OF KNOWING THERE ARE TWO VERSIONS OF YOUR ARCH-NEMISIS AND ONE OF THEM IS ROAMING FREE, IT'S A WONDER YOU'RE NOT MORE INSANE!"
Bill kept prodding around Artemis's mind for a while, finding more and more the kid was guilty about. Between the guilt, the stress, the magic invading his mind, and his own smarts, Artemis was a perfect recipe for disaster. "OH, I WISH I HAD MORE TIME TO PLAY WITH YOU!" Bill said. "TOO BAD I HAVE OTHER PROJECTS TO GET BACK TO SOON. STILL, I'LL SET SOME FUN IN MOTION AND CHECK BACK LATER!" Bill accessed the dimension's networks to get information on Artemis's condition. "ATLANTIS COMPLEX… USUALLY ASSOCIATED WITH MULTIPLE PERSONALITY DISORDER IN LATER STAGES… LET'S SEE IF I CAN'T SPEED THAT UP!" He dove right into the most infected parts of Artemis's brain. "NOW, I'LL JUST CREATE A NICE LITTLE ALTERNATE PERSONALITY FOR YOU. TRUST ME; IT'LL BE WAY BETTER THAN ANYTHING YOU COULD COME UP WITH ON YOUR OWN!"
To start off, Bill took a side-trip into the part of Artemis's brain where his identity was rooted. He'd have to spread the infection to this part for the other personality to get any real hold, but that was step two. Step one was to make the personality. Bill knew, however, that he had to use some pieces of Artemis's existing self-identity, or else his mind would reject the alternate. Bill saw Artemis's name plaster all over his own mind and commented, "GEE, IT'S FUNNY HOW MUCH YOU THINK ABOUT YOUR OWN NAME!" Bill had a vague feeling that he would think that about someone else in the future, some other smart kid, but just as soon as Bill tried to focus on the thought, it slipped from him. Seeing only tiny fragments of the future was annoying, like having déjà vu but not knowing what you were remembering. Shaking off the premonitions, Bill set to work observing Artemis's own thoughts about his name, ranging from pride for having the name of the hunter to shame for having a goddess's name. Bill knew he could use this bit of information about Artemis's name. "NAME OF A GODDESS? WHO WAS SHE RELATED TO IN MYTHOLOGY…? AH, SHE HAD A TWIN, APOLLO. SOUNDS FUN… EXCEPT THAT I HATE TWINS. NO KIDS, NO OTHER FULL SIBLINGS. HER ALTERNATE NAME IS DIANA, BUT THAT'S TOO GIRLY FOR HIS MIND TO ACCEPT AS A PERSONALITY." Bill was about to give up and go ahead and make the personality Apollo when he stumbled across the name Orion. "OOH, STARS! I LOVE STARS!" He tabbed through Artemis's memories of the mythological story, and if he could have grinned, he would have. As it was, his eye was expressive enough to show his pleasure at the find. "ORION WAS ARTEMIS'S FRIEND AND ARCHNEMESIS? THAT'S JUST TOO PERFECT!"
After rifling through everything else that, in Artemis's opinion, made Artemis who he was, Bill figured he had all the information he needed to get started. "FIRM GRASP ON REALITY? UNCHECK!" Bill said, crafting Orion to not know the difference between the real and the unreal. "SMART AND WISE? UNCHECK!" Bill took Artemis's IQ and halved it for Orion before subtracting more to leave Orion with under average intelligence, as opposed to Artemis's IQ, which was just about twice that of the average human (or, at least, Artemis thought it was twice that of a normal human's IQ). He also took away all common sense, leaving Orion as a clueless little dummy. Bill kept on like this, shaping Orion into the maximum chaos-causing being possible. "OH I WANT TO BE THERE WHEN YOU FIRST EMERGE!" Bill told his new creation. "ARTEMIS'S FRIENDS AND FAMILY WON'T KNOW WHAT HIT THEM!" Satisfied with his work on Orion, Bill added a little more chaos by planting seeds of doubt in Artemis's mind about whether or not he could trust his friends and family. He knew it would take a while for Orion to develop in Artemis's mind, and even longer before he was ready to take over, but Bill was okay with that. He just hoped he wouldn't be too busy to see it happen. "WELL, THAT WAS FUN!" Bill said. "BUT IT'S TIME TO GO BACK FOR NOW. YOU KNOW, DEMON POLITICS AND ALL. SEE YOU LATER, MINI-TUX. UNTIL NEXT TIME!" With that, Bill left dimension 55\EC and went back to the Nightmare Realm.
Artemis woke with the vague feeling he'd had a nightmare, though he couldn't remember what it was about. The only clear thought in his mind was, "I can't trust the number three either. Four is death, but three is evil, too. Three is evil. Three is evil and four is death. Only five can save me. Only five can save me." As Artemis rubbed the sleep from his eyes, he realized just how crazy those thoughts sounded. "Get a hold on yourself, Artemis. Numbers don't matter. The Illuminati doesn't exist. You're fine." Then he thought, "Wait, I wasn't even thinking about the Illuminati. Where did I get that from?" From the back of his mind, Artemis could almost hear inhuman high-pitched laughter.
I hope you enjoyed this. Just a couple things to note. 1: I actually do not know the Dimension number for the Nightmare Realm. I just chose a number that fit with the story. 2: I did my best to line up the timelines, assuming that the year the first Artemis Fowl book was published was the year it took place in, but I may have gotten the years and ages off by a bit.
In any case, I hope you enjoyed it, and I'm planning to post more stories in the future, though I am not planning to continue this one. Just assume that Bill watched the Orion mess from the sidelines with amusement, but didn't interfere, since he has no particular interest in that world.