A/N: This is an Invader Zim/Fairly OddParents crossover, but it's highly centered on IZ. It takes place long after the FOP canon so most characters from that show are not going to show up (this is more of a crossover with the universe than the specific canon, except for an older version of one character).

It was going to be a bad day. That much was evident. Dib regarded the woman at the front of the classroom—standing ramrod straight, ankles together, hands clasped behind her back, spectacles perched on the bridge of her nose. And yes, they were definitely spectacles, not glasses.

"I am Ms. Bridgewater," the woman said in a clear voice to the class. "I will be substituting for your usual teacher, Ms. Bitters, who seems to have gotten 'fed up' with you children and locked herself in the janitor's closet to contain her anger. Apparently everyone is too afraid to try to get her out. I will now call roll." She whipped a piece of paper seemingly from nowhere and scanned the list. "Hm… your last names are not given… Very well… Aki? …Brian? …Carl?"

A chorus of 'here's rang out as she called the names. Then she came to a spot on the list and paused. "…Dib." She raised her eyes and glared right at him. "Your reputation precedes you."

Dib started. Reputation? That couldn't be good. Maybe she'd heard about the vampire gerbil incident. Or maybe the FBI had told her about the Ninja ghost that Dib had spent three carefully-planned months getting rid of!

"I've got my eye on you, young man," Ms. Bridgewater said with narrowed eyes. "I know what you've done in the past and bullying is not tolerated in my classroom."

"What?" Dib spluttered, shocked to the core. Bullying? Huh? People had complained about him before, plenty of people, but it was usually for something like 'chattering' to them about the different types of poltergeists when they weren't in the mood to hear it. "Ms. Bridgewater, I don't know what—" Dib stopped. The substitute had started calling out the next few names. Dib had interrupted her.

Ms. Bridgewater raised her eyebrow at him, hmphed, and continued reading names. Dib was left to ponder what she had meant. Maybe she had been talking about people bullying him, which happened occasionally. (Usually people just went out of their way to avoid him.) But then… why had it sounded like she was angry with him? Odd.

Ms. Bridgewater reached one of the last names on the list. "Zim!"

Her entire demeanor changed. She smiled, an actual, warm, friendly smile, and literally ran over to Zim's desk. "Sweetie. I've heard about you. How are you doing today? All right?"

Zim leaned away from her. "Heh?"

"I've heard about you, too, child. And about your—" Ms. Bridgewater's voice dropped to a whisper, "—condition."

Zim gawked at her without comprehending, then cleared his throat. "Oh, erm, yes, it's, eh, horrible." He was still straining backwards as if desperate to get as far away from the woman as he could without leaving his chair.

"Poor baby." The substitute's eyes were sorrowful. "If there's ever anything you need, let me know right away."

Dib raised his hand—really just as a formality because he went ahead and talked without being called on—and said, "Ms. Bridgewater! That's not a skin condition. He's an alien!"

And the walls came down.

"DETENTION!" Ms. Bridgewater spat, all traces of kindness vanished. She strode across the room and leered down at Dib. When compared with the terrifying glares Ms. Bitters would give the class, hers was kind of pathetic, but where Ms. Bitters' voice was a loud rasp Ms. Bridgewater's shout was a piercing screech. Dib recoiled.

Giving her a bewildered stare, he said, "But I—"

"You will stay in this classroom during lunch and recess, and after skool!" Ms. Bridgewater said.

Dib took a shuddering breath. "Yes, Ma'am."

The class sat stock-still. Ms. Bridgewater finished the roll, then tried to figure out what to do with the herd of fifth-graders blinking owlishly up at her. Apparently Ms. Bitters hadn't left a lesson plan.

Something hit Dib in the back of the head, to a small eruption of snickering. It was a ball of paper. Dib smoothed it out and saw that it was a note. A note saying, "That's what you get for always picking on Zim!" except most of the words were misspelled and the handwriting was so sloppy Dib could barely read it. Dib glanced around the class and saw that the note could only have been from… Chunk. The guy who picked on anyone smaller than him every chance he got! Typical. Dib crumpled the paper up again and dropped it on the floor.

Picking on Zim. So… not only were his attempts to protect the Earth from a race of imperialistic aliens ignored and even hindered by the people around him, it was considered bullying? Zim wasn't even a real kid! Who knew how old he actually was?!

After that the class passed uneventfully. Dib, having no intention to be yelled at again, said nothing else. The bell rang and the room filled with shuffling noises and voices as everyone stood and headed out, toward the cafeteria. Dib remained in his seat.

The classroom emptied. A few seconds passed before a shadow fell over Dib—Ms. Bridgewater had stepped in front of his desk once more.

She got right to the point. "Dib. I have heard what you've done to Zim, and what you've said to many other children in this Skool. Calling them aliens? Saying their parents are yetis?"

Dib turned his gaze up to hers. "Ms. Bridgewater, I'm a paranormal investigator. Everything I've said is—"

"—Is bullying!" the substitute snapped. "You're no investigator. You make up lies about your classmates and try to spread the rumors. Poor little Zim is very sick with a serious medical condition, and I have footage," her face flushed with anger, "Footage of you, dumping water on him, throwing food at him, kicking him, and tying him to the tether pole!"

"It's not a skin condition!" Dib said desperately. "He's an alien!"

The substitute's voice rose even higher. "I DON'T WANT TO HEAR IT! You are the monster, not your classmates like you try to convince everyone! You are one of the most despicable creatures I've ever seen in my entire substituting career! A BULLY!"

She glared at Dib's sheet-white face for a moment. Then she went and sat behind Ms. Bitters' desk like she owned it… like nothing whatsoever had happened… like a young boy's heart hadn't just shattered.

Dib was gripping his own desk so hard that he thought part of it might break off. He couldn't even seem to remember how to breathe.

"Ms… Ms. Bridgewater…" His voice came out as a croak. "I need to use the restroom."

Ms. Bridgewater waved toward the door. "Go, just be quick about it. And if I get one complaint about you from another student…"

Before she could finish, Dib jumped up from his seat and left the room as fast as he could without running.

He stumbled into the boys' bathroom glassy and as if in some sort of trance. The bathroom was empty. He dashed into one of the stalls, slammed closed the door and locked it. He leaned his back against it. His breath came out in short gasps now. And his eyes stung. He sank to the ground, burying his head in his hands, and gave himself over to sporadic shuddering.

But he wouldn't let himself cry. Not again. He let out a long breath through his nose.

I wish Ms. Bitters was back.

Some hours later, Dib opened the door of his house and stood lamely in the entryway. Ms. Bridgewater had kept him after skool until the sun had gone down—he'd had to walk home. In the dark.

He wandered into the living room to see Gaz sitting on the couch watching TV.

"You're quiet," Gaz said, not looking up at him. "For once."

Dib rubbed his forehead. "Look… Gaz, I really can't do this today. Okay? Please?" She hadn't even asked why he was home so late. Maybe she was used to it.

Gaz shrugged. "Hey, I'm not complaining."

"Is Dad here?" Dib asked.

"No. He's not coming back for three more weeks, remember? Oh, and I recorded over your stupid Mysterious Mysteries today. The nature channel was broadcasting a documentary on piranhas."

Dib didn't say anything. He just turned back the way he had come and headed up the stairs to his room.

For a long while he just stood in the middle of the floor, staring at nothing, his stomach churning. Then he ran across the room and grabbed the nearest case file on his desk.

"This is the last straw!" he shouted, flinging it at the wall. Papers, newspaper clippings, and blurry photos flew everywhere. Dib huddled on the floor, pulling his trench coat tightly around him. The last straw for what? He didn't know. But it was too much! Detention? A new Mysterious Mysteries episode that had been deleted for a piranha documentary?! And the teacher! Even Ms. Bitters, as intimidating as she was, had never screamed in his face! The worst thing she had ever done was make him clean Zim's puss-mess with a—ew, EW, no, never mind, he was never going to think about that again.

Someone knocked on the door. Dib jerked his head up. "Huh?"

"Dad called on the hover screen and says to eat leftovers instead of ordering pizza again," Gaz said from outside. She sounded disappointed.

"…Okay, sure," Dib said, but Gaz didn't respond. She must have already gone back downstairs. Dib stood back up, gulped, and tried to regain composure.

At least he'd never have to see Ms. Bridgewater again. She was a substitute. Tomorrow, Ms. Bitters would be back, and Dib would be back to dealing with the old horrors instead of these new ones.

Dib caught sight of the case file he had thrown, with its contents strewn all over the room. He shook his head and rushed over, picking up the papers, trying to reorder them, putting them back in the folder. Inwardly he berated himself. How could he have treated such important documents so carelessly?

Then the folder began to glow with a blue light.

Whoa! Dib snatched his hand away and stared at the folder. What was causing that?! Spirits? Ectoplasm? Alien technology? What was going—

Glittering trails of light burst up into the air from the folder. They spiraled together and shone brighter than anything Dib had ever seen. He squinted. And then… and then a person appeared out of the light. A little person, about the same height as Dib, with large eyes the same color as its light purple hair. The light disappeared. Dib rubbed his eyes under his glasses and blinked. The person was holding a cheesy looking wand-thing with a star on the tip, and had a little gold crown floating above its head.

"Hi!" the person said in what Dib presumed to be a somewhat masculine voice. Somehow the person was still floating. Was this some sort of trick? A hallucination? Something paranormal? Whatever it was, it couldn't be what it looked like…

"What are you?" Dib asked faintly. He hoped it wasn't a poltergeist. He really wasn't in the mood to deal with one of those right now. The thing drifted closer and Dib saw that it had little iridescent bee-like wings whirring on its back. Despite the speed they were moving, they made no sound.

"I'm Poof!" the fairy said, smiling. "And I'm… your fairy godparent!"