There's Something Inside Your Head (Invader ZiM AU)

(CW: even more death...in a kind of disturbing way.)

ZiM was a bit relieved when he woke up alone. He thought maybe it was just a dream—though, he wasn't exactly what dreams were like, since he never slept before. It had all been so weird, and he didn't know what to make of it... he did miss Dib, however, but didn't really want to talk to Pilot. He didn't want to face him.
Throughout the day he had tried to forget about it all, focusing on what was really important: what he would do now that he's on Earth for maybe forever.
Would he stay with Dib? Would he go to another place on Earth? He had been in the same place for six years now... maybe it was time to move. Maybe. What would Dib think? Would he come with him? Would he not like it? Would—
No, stop thinking about Dib, ZiM. This isn't about him, it's about you. Though, with what's coming up, I'm afraid you'll be as stupid as you are here.
What's important is that ZiM will be leaving.

ZiM paced back and forth in his house, alone, hours later, thinking the same thing over and over: "Will I leave? Will I leave?"
His answer would come, in 3... 2...

"ZiM!" A familiar voice came from his monitor, causing the Irken to snap out of his small trance. "ZiM, are you there?"

ZiM rushed into the main room, only to be met by Skoodge on the screen. "Yes! It is I! Eh, what are you doing here..?"

"So! Good news! I found an extra working ship on a nearby planet—I can send it to you, but.. you can't exactly go back to Irk. But don't worry, because it can go literally anywhere else! You don't have to be stuck on Earth any longer!" He smiled, sitting a bit close to the camera.

ZiM's eyes widened, and his shoulders relaxed entirely. "ZiM.. can leave?" His antennae slowly raised, and he hardly noticed the growing relief in his squeedlyspooch. "Really?"

"Yeah! Really! If I put in your location now, it could be there by tonight! You want it?"

ZiM's antennae shook a bit. "Yes, yes of course ZiM wants it! Yes!" He stood on the edge of his boots, his arms bent up in front of him. "Give to ZiiiiM!"

Skoodge laughed, "A 'thank you' would be nice."

"Oh, come on, ZiM thanks no one!" ZiM grinned. "But... thank you. Really."

"Sure, dude— oh, hey, I gotta go, I have another call!" Skoodge waved, then as quick as he came, he was gone.

ZiM stood there, staring at the screen playing white noise as his positive feelings hit him all at once. He didn't dare move; he was up straight, staring straight forward, feeling as if he was being held up by a tall string. He would be leaving soon, he would be able to do whatever he wanted.

Oh, but Dib.

He had to tell Dib.

When? School didn't start until tomorrow.. why rush it? Or, should it be rushed? When was ZiM going to leave, anyway? The ship would be there by that night, that gives enough time to say goodbye, right? Besides, that PAK numb-er was still attached behind his PAK—he needed to get it out.

Stop it. This was no time to think about him.

ZiM was finally going to start a new life.

That's what he needed, right? It's what he wanted? After the Tallest cut him off, he needed something else to do... he had thought going to serve another leader would fill the missing needs, but all it did was just make his longing worse. He wanted to do something else, not continue to do the same thing.
But obeying was what he was good at—it's what he was programmed to do.
But he has no one he really needs to obey, does he? He follows Pilot, but doesn't need to. He won't die without him, so why stay around?
It was time for something new, time for what he's been waiting for. He would stay alive to the end of the story.