Author's Notes: This is a new idea I had, but I really like this one. It's kind of an odd story though, I admit. Hopefully it will be one you guys like though. I won't say too much right now because I don't want to give too much away. I just want to say thank you for reading, and I hope to read your reviews :)

Chapter 1

Back To Skool

The sky was still partially dark when Dib awoke from his slumber by the sound of his annoying alarm clock. He groaned for 5 more minutes and fumbled to turn off the offending time telling device. When he reached too far, however, he fell of the bed in a mess of limbs and covers; jolting himself awake and hurting his big head.

"Ow, well, I guess I better get up anyway," Dib mumbled to himself as he stood up.

During summer vacation Dib had gotten used to sleeping in until the afternoon and staying up all night watching Mysterious Mysteries. Oddly enough his summer had been peaceful, as Zim hadn't emerged from his home once the entire time.

Dib was relieved the earth didn't explode, but was also kind of disappointed that his summer had been wasted searching for an enemy that never came. It reminded Dib of the time Zim spent months hiding in his own toilet just to get Dib to atrophy in his chair. Dib couldn't help but think Irkens were strange creatures. Or maybe it was just Zim. Dib had no way of knowing since he'd only met Zim and Tak.

Tak. There was a name he hadn't thought of in years. Dib was 16 years old now, and when he met Tak he had just turned 12, so...4 years. Dib was surprised it had really been 4 years since they had stopped Tak's evil snack plan and he had acquired her spaceship. That thing came in handy when stopping Zim's space-based plans, but it still had a few glitches even all these years later. Also it was a tighter fit now that he was older. The thing was built for little Irken bodies, not fully grown humans.

Dib brushed his teeth, ran some gel along his scythe-shaped hair, and washed his face. He had to get dressed and get breakfast before the skool bus came. He was just glad it was still early enough, but he felt so tired from the long night before. He had spent way too much time online checking the Swollen Eyeball forums and then checking one more time to see if Zim was planning something. He still didn't see anything, and wondered if he should try to get another spy cam inside Zim's base.

"Not a good idea," Dib said to himself, "He's beefed up security, so I'd probably get caught."

Ever since Dib's growth spurt he wasn't as limber as before, and therefore wasn't as adept at sneaking around Zim's house. Dib chuckled to himself when he remembered the last time he saw Zim in skool. Everyone else was going through puberty while Zim stayed small and glowered at the giants he was forced to attend skool with. Dib honestly wondered why Zim still bothered. Skool clearly wasn't helping his plans for world domination. Then again, maybe Zim just wanted to keep an eye on Dib the same way Dib kept an eye on Zim.

Dib got dressed and went downstairs. Even after all these years Dib still liked to wear a black trenchcoat. It made him feel like Neo from The Matrix or some other super hero that had information no one else did. He put on his boots and ran to the kitchen to get breakfast.

Gaz was sitting there eating toast. Of course she would only make toast, and of course she wouldn't make any for him. Dib sighed and grabbed a bowl and filled it with cereal. Gaz was looking down at her tablet reading a gaming forum, which was pretty typical of her. Since she had become a teenager she didn't wear as many goth clothes as she used to, but she was still way into gaming culture and still scared the living daylights out of everyone she knew.

"Hey Gaz, where's the bread? I wanna make toast," Dib asked.

Gaz just growled in reply, telling Dib that she really wanted to be left alone. Dib sighed and just ate the cereal. The milk tasted a little sour, but Dib put up with it. After all, it had been his responsibility to buy the milk. He brought it on himself.

When Dib got to skool he was almost excited. He was curious to see if any of the new students in his class would want to hang out with him, and if Zim was going to bother to show his ugly green face. Yes, it was a bit of an obsession, but Zim was an evil alien monster bent on destroying mankind. Dib could afford to be a little obsessed if it meant the safety of billions.

Dib made sure to claim the desk at the front by the window. It was where he was most comfortable. He looked out and saw that his high skool overlooked the sausage plant. The horrible stench was enough to tell him that, and hearing the squealing pigs just made the whole experience worse. Dib sighed. Well, this was just going great so far.

He decided to look at the door to the classroom instead; hoping to get his mind off the pigs. Most of the kids that saw him staring either backed away feeling disturbed by his attention or else sniffed at him in disdain. Dib's reputation as the crazy boy followed him even now in high skool.

"Class, everyone take your seats," The teacher ordered them as he twitched his messy mustache, "Greetings children, I am Mr. Howkins. For the next skool year I will expect you to pay proper attention and have your homework in on time. Now, to call role. Ashy?"

"Present,"

"Billy?"

"Here!"

"Dib?"

"Here, Mr. Howkins."

"Enna?"

"Present."

The role was called until the teacher got to the last name.

"Zim?"

No answer.

"I said, Zim!"

Nothing.

The teacher was about to mark the boy absent until the door suddenly swung open and a very tall skinny green kid leaned against the wall panting for breath. Dib looked at the green skin, black wig, and stupid pink shirt, and did a double take. Something about this didn't seem right...

"Let me guess, Zim?" The teacher asked wryly.

"Huh? Oh, yeah. Sure. That's me," The voice that came out of Zim was somehow even squeakier than the one he had before, and it kind of made Dib think of that ugly purple dinosaur puppet he and Gaz watched on TV when they were little, "Sorry I'm late, sir. I couldn't find my class."

"Well hurry up and take your seat, Zim. We don't have all day," The teacher replied irritably, "Now that everyone is here, we can begin."

Dib wasn't listening to the teacher, as usual. He stared at Zim, and felt the wrongness in the room. This new Zim didn't set well with Dib. For one thing, Zim was much, much taller than he had been two months prior. For a normal kid they could claim it was puberty, but Dib knew enough about Zim's species to know growth hormones weren't guaranteed and had nothing to do with age. Irkens didn't grow often, and when they did it was almost completely random. Growth almost seemed like a mutation, but then again Dib didn't know enough about it to be sure.

Maybe Zim developed some experimental growth formula to try to make himself earth's leader... Dib thought. No, that's stupid, even for Zim. Wait, what am I saying? Nothing's too insane for Zim! Okay, so that would explain his height, but why did his voice get derpier?

Dib continued to stare at Zim, and the more he stared the weirder he felt. This Zim had the same cruddy disguise as before, but something seemed off in the eyes. The contacts were the same color, but the light reflected off of them didn't have the same intensity. The way this guy carried himself also seemed different. This kid seemed less sure of himself, more subdued. He was being quiet, too. Zim was never quiet! The new guy, for it simply couldn't be Zim, wouldn't even look at anyone. He just stared ahead at the chalkboard with a faraway expression on his face.

Dib wanted to scream at this new alien to explain himself, to demand to know what Zim's next evil plan was and what it had to do with hiring a replacement for him in class, but he stopped himself. With Ms. Bitters Dib could interrupt all he wanted because she didn't care if her students learned or not. With other teachers though, Dib had to be more careful. He could wait, and he would wait for the perfect moment to expose this new alien imposter.

The lunch bell rang and Dib was ready. He was going to confront the new Zim in the cafeteria where they could talk freely. He would get to the bottom of this, or his name wasn't Dib Membrane!

Dib was shoved to the back of the line by hungry kids, so by the time he got his food Gaz was already sitting with her other gamer friends. Looked like Dib would have to search for an empty table, and he knew just where to do that. Zim, because other kids thought he was a freak, often had an entire table to himself. Today was no different. Zim was alone. One thing was different about today though...

Zim was actually eating the food! Not just eating it, but shoveling it in like he had never tasted food before in his life. Dib openly gaped. Every time Zim sat down in the lunchroom he would order food but then proceed to poke it with a fork and never actually eat anything. Most earth foods were either dangerous to Zim or else just tasted bad to the Irken invader, but the new Zim didn't seem to notice or care. Dib had had enough of this charade, and decided to confront the imposter now.

"Hey, Zim," Dib said the word Zim with openly sarcastic venom as he sat down, "You enjoying your food, space boy?"

"Uh, 'pace b'y?" New Zim questioned; his mouth full of peas. New Zim gulped down the food before continuing to speak. "Hey, I know you! Get away from my table, big headed boy!"

"My head's not big!" Dib retorted automatically, "Look, I know something's up. You never eat the food here. You've often said that it burns and that it makes you sick. So, why now?"

"Actually, the food here is awful," New Zim admitted, "But I haven't eaten in...how long is it in earth time?" He calculated on a device on his wrist that appeared out of nowhere, "Um, three and a half earth weeks. Yeah, that sounds right."

"Three weeks?" Dib asked incredulously, "Wait, how long does it take an Irken to starve?"

"I hope I never find out," New Zim shuddered, "I mean, I don't know what you're talking about! I'm not an Irken. I'm a...a...aw, crud! I forgot the name of our species! What are we called again, big head?"

"My name is Dib and I am a human!" Dib shouted angrily, "Look, I don't know what's going on, but you're not Zim!"

"You sound disappointed," New Zim replied sardonically as he rested his head in his hand, "Look kid, I am Zim and I am human. That's all you need to know. Now leave me alone to finish off my filthy food. I still have to figure out how to tackle the meat. Ugh! Meat..."

The way this guy spoke wasn't with the screaming energy that Zim had. He was calm and almost patronizing, but not what Dib would call hostile. Was this guy even an Irken? Did Irkens even reach the size of human adults? A question remained though, and Dib had to voice it.

"Why?" Dib asked suddenly after a few awkward moments of silence.

"Huh? Why what?" New Zim asked.

"Why Zim?" Dib asked, though he knew he sounded stupid as soon as he opened his mouth, "I mean, I know you're not the real Zim. Why pretend to be Zim? Why him?"

The new Zim scowled, and his eyes took on a darker quality as he glared at Dib.

"Look you, I've had a really bad time lately," New Zim hissed; his voice almost sounding deeper than Zim's now, "I don't want to talk to you, I don't want to look at you, and if you don't want a closed casket funeral with no one left in your city to attend you will Leave. Me. Alone."

Dib would normally see Zim's threats as a challenge, but as mentioned before, Dib was convinced this wasn't Zim. Not to mention, he sounded pretty serious. Dib, deciding he would check back on this later, left the table and ate out in the hall instead.

Back in class, Dib was trying his hardest to pay attention despite the gangly Zim impersonator in the room just across from him. The conversation in the lunchroom left behind more questions than answers. He knew this guy wasn't Zim, but then who was he? Why was he here? It reminded Dib of when he first met Zim. The rush of excitement and the fear of that had almost been forgotten since Dib had been fighting this private war for so long, but now he remembered what it felt like to have a strange alien presence in the classroom. It had been unnerving yet gave him a welcome rush of adrenaline, and that was what he was feeling now.

"Alright class, your first homework is for you to write an essay about what you did over your summer vacation," The teacher informed his students, "It can be about a trip you took, a special experience you had, anything. Just be sure to flex those creative writing muscles. Hopefully you kids will think of it as a fun project."

Dib was trying to listen, but he couldn't help but look over at Zim's desk. New Zim was writing something on a piece of paper. He seemed to be holding the pencil in his fist like some kind of toddler. This was just embarrassing, even for him. Dib wondered if it was some sort of plan for world domination, or maybe a message for the real Zim. Dib had to find out.

The skool bell rang and the kids cheered and clamoured for the front door. It wasn't dignified, but Dib was used to his classmates acting like animals. He went a little slower than the other kids to avoid getting stuck in the door during the rush. As he finally turned to go he noticed that New Zim was walking up to the teacher.

"What is it, Zim?" Mr. Howkins asked in a haggard tone of voice.

"I finished my essay," New Zim replied; an oddly begrudging frown on his face.

"Already?" The teacher asked with eyebrows raised in mild surprise.

"Yeah, I don't feel like wasting my time on this, so can you just take it now?" New Zim asked grumpily.

The teacher harrumphed and took the paper from New Zim's grasp. He read over the paper and said "Very funny mister. This is too short and too sarcastic. You need to do it for real."

"You didn't give a word count, and that really was my summer," New Zim shrugged in a condescending way, "Take it or leave it, skool beast."

Dib couldn't contain himself anymore. He surreptitiously snuck behind the teacher's chair so he could read what New Zim had wrote. Fortunately New Zim and the teacher were too busy with their argument to notice him. Dib read the words, but it took a moment before they registered.

What I did in the summer. My best friend died and I lost everything. The end.

The penmanship was utterly juvenile with large shakily written letters, and the vocabulary was simple and abrupt. It reminded Dib of those investigation TV shows where a little kid will try to write down details to a crime. This definitely wasn't Zim. These were the words of a simple heartbroken soul. Yet the creature standing there arguing with the teacher seemed like nothing of the sort. He was snide, rude, and had a voice that could grate on anyone's nerves. Dib had to remind himself that whoever this was, he was an Irken invader, and therefore not innocent.

"Dib, is there something you need?" The teacher asked as he turned to glare at the student behind him.

"Um...I was just wondering...are photos allowed when presenting our homework?" Dib asked on the fly to avoid being caught staring at New Zim's paper.

"Yes Dib, they are allowed," The teacher replied wearily, "Just no videos."

"Understood, Mr. Howkins," Dib replied politely, "See you tomorrow."

Dib then ran out of the classroom, his head still reeling. Who was Zim's best friend? Did Gir die? Wait, maybe Zim died and his best friend replaced him. Dib had trouble imagining that little green headache had friends. Who was this new kid? Why was he here? Where was Zim? Also, was earth in more danger or less?