Invader Zim: The true invasion (IZ fanfic)

Chapter one

It was a normal day at Skool. The class was taking a test since Miss. Bitters finished explaining the lesson durring last class. Most students were clueless about the test since Miss. Bitters forgets to notify the class about up coming tests and exams as a routine. Dib and the other kids were just as frustrated and bitter as Miss. Bitters herslf, but not Zim. Zim, this little alien, the space boy, somehow managed to stay focused. More than that, he understood the assignments and halfway through class, he raised his hand, signalling that he wanted to say something

-Yes, Zim ?-Miss. Bitters called on him.
-Miss. Bitters, I am done with the test.- Zim said in a very comfident, yet ordinary tone while raising the test with the same hand he raised a minute before to ask for speech.
-Impossible...-She said as she rushed up to Zim's desk to check his paper. Meanwhile Dib was whispering to the kid sitting next to him.
-Bet he finished early 'cause he didn't know a single thing.- He said, all the while the class fell totally silent as the teacher looked through Zim's answers one-by-one.
-Impossible...- Miss. Bitters said once again as she flipped between the two pages of the test, but in a different way. She seemed confused, almost lost.- Your answers are...- The class stared at Zim and the teacher in agitated silence as Miss. Bitters was about to finish her sentence.- All right... Each and every one of them...- Miss. Bitters said in disbelief as Zim covered his mouth with his hands and let out a quiet, mischievous laugh.

a quiet roar of surprised, confused and curious whispers  brushed through the class as Miss. Bitters took the papers to her desk to look over the questions and answers once again, very carefully. Dib was visibly upset. He studied for the test all night and even then, there was no way in heck he was even gonna get a "B+". Miss. Bitters never gives too good grades, but if Zim's test really was perfect, she couldn't just give him anything other than an "A+", right ?

-ZIM! EMPTY YOUR DESK AND BACKPACK !-Sorry! I forgot we're talking about Miss. Bitters here. She stood up from her desk, and demanded Zim to prove he was not cheating. From that the class assumed that his test really was flawless. Zim just calmly stood up and said:
-You are free to look over my stuff, miss...- And she did, but after 10 minutes of searching, she couldn't find anything against him. The class was quietly snickering at this point. It was just so absurd for someone to get a perfect grade from Ms. Bitters that it was almost funny.
-So... you weren't cheating...- Miss. bitters straightened up. She dug through his backpack, desk and just for the fun of it: Zim willingly emptied his pockets to prove that he really had nothing to hide.
-Not at all, miss !-Zim declared with a straight face.
-...Okay, Zim ! Sit down !...

She let out a defeated sigh as she walked back to her desk and wrote the "A+" on Zim's paper. Dib threw a crumpled up piece of paper at Zim. He threw it pretty hard. Zim looked around the class to see who threw the paper and met Dib's death glare, staring back at him. He opened up the paper. It read: "Meet me after class !" and the little message also contained a skull, clearly drawn by Dib himself.  Even in his writing, you could clearly see that he was furious. Zim rather than feeling superior, he felt frightened. Zim was just drawing in his sketchbook for the rest of the class. When the bell finally rang and the papers were collected, Dib was the first to get to the door, He stood right next to the doorway, not taking his eyes off Zim. Not for a second. Zim was just quietly sitting at his desk, drawing on, pretending not to notice Dib and his very intence stare, when deep down, he knew there was no escape from having to talk to him. When everyone finally left, Dib finally had the greenlight and went up to Zim's desk and leaned over him, his shadow burrying him. Zim looked up at Dib, and instantly closed his sketchbook.

-how did you do it ?- Dib asked the obvious question.
-What ?-Zim asked like he didn't know exactly what Dib was talking about.
-Don't play dumb, Zim ! You know exactly what I'm talking about.- Zim softly shook his head as he was holding his sketchbook in between them as a barrier for a little sense of protection.-HOW DID YOU GET THAT PERFECT SCORE ?!-Dib raised his voice at Zim.
-I'm smart ?...-he responded, but sounded more like an uncertain, quiet question than an actual statement.
-YOU'RE NOT FOOLING ME !- Dib shouted as he ripped the sketchbook out of Zim's hands and threw it across the classroom. The sketchbook landed open, face up.
-NO ! MY SKETCHBOOK !- Zim reached after Dib's hand as a reflex, but he was too slow. Dib looked at him for a second, then back at the book and he pushed Zim's desk onto him, trapping him, before scooping up the book and running out of the class.- HEY ! GIVE IT BACK ! IT'S MINE !-Zim screamed before getting up from his desk to chase after him and get his skecthbook back.