/071. Broken
The cast on Dib's arm was chunky, white, and totally unmarked. Zim couldn't stop staring at it.
Humans had funny customs. They liked to mark things. Any other kid, and the cast would have been covered in doodles, signitures, tic-tac-toe games, orders to get well soon, meaningless scribbles... but Dib had no friends, and his cast stayed clean. The human just propped it irritably on the edge of his desk, making a face at how it restricted the room he had for his textbook and notebook, and otherwise he managed to ignore it. The broken arm wasn't the one he wrote with, so he could manage.
Zim sidled up to him at lunch, clutching a black sharpie in one hand. He'd finally decided that, really, he wanted to do something about that whiteness. He wanted to show off, in some way only the two of them - Dib and Zim - would understand, that he'd been the cause of this injury, that he'd ruled what happened to Dib during those moments.
The cracking bone had been such a pleasant noise. Dib's scream, even more so.
So he joined the boy at lunch, giving him a wide, nasty grin. Dib eyed his enemy warily. Zim had sat on his left side - the side with the cast. It was less agile, unguarded.
"Helloooo, Dib," he cooed. This boy, here, this tensely-sitting wary twitching boy, was not his enemy. This child was a joke. Boy with useless arm tries to stop amazing Irken Invader. Boy is crushed horribly. Ahahaha. This was a person who was worthy of being cooed at. "Arm feeling any better?"
"Fuck you," Dib snapped back, shoving his tray away across the table. "Yeah, my arm's feeling fantastic. Second this cast gets off, I'm going to, I dunno, install some pins and stuff to reinforce the bone and beat your ass with it. I can't believe you did this."
Zim reached over, tapped his fingers on the hard shell. "Get well sooooon," he grinned. "I guess I'll just have to get busy taking over the world without you."
Dib threw one leg back across the bench, clenched his jaw, and glared. He was feeling pissy and ready to get out of there. Zim grinned and snapped one hand out and pinned Dib's arm to the table; he uncapped the sharpie and scrawled onto the cast -
Lightning-bolt Z, boring boring letter I, M like mountain. ZIM. Beautiful.
"Get well, get well," he sang cheerfully to the furious human. "It's not any fun without you around."
The next day, Zim's name was scribbled out in a blob of black that reached tendrils all over the cast. The evidence was gone, but both of them still knew.