The first thing Dib got when he arrived at the base that day was a pillow chucked directly at his head.

"I hate you!"

Dib let the pillow flop to the floor, checking his glasses for cracks. An old habit, even though the new reinforced glass could probably remain intact if he stepped on a land mine and it was the only thing left of him. "And what do you hate me for?"

Zim was on his stomach on the couch, face planted firmly in the remaining pillow. Dib wasn't sure if he should be putting all his weight on his front side like that, but the cushions were pretty soft. It was probably fine.

"Do you know what happened an hour ago?"

"I'll bite. What?"

"I got sick. In front of the Tallests."

Dib raised an eyebrow. "Didn't you say you contacted them while still wearing that weird napkin-meat suit once? They're probably used to weird stuff from you."

"That's not the point right now! I need to look strong in front of them, or they'll reassign me!"

"You'll be fine, Zim." Dib set a hand on Zim's back, but with a snarl, Zim batted it away.

"Do not touch me! You already poisoned me with your vile fabric of evil!"

"Fabric of evil?" Dib looked around, spotting his discarded shirt. "Oh, hey, that's where that went." He grabbed it. "I didn't do anything do it. Why?"

"It made me gooey. I didn't like it." Zim flipped himself over, staring up at Dib. "Too gooey…"

"Gooey how?" Dib pulled out his notebook, but Zim swatted that away too. "Hey!"

"Stop taking notes, this is the time for me to blame you!"

"Geez, fine. You're moody today."

Zim sat up, glaring at him. "I'm not moody, I'm sick and it's your fault! Everything's your fault! I couldn't finish this mission yet because you were always there, and now parts of the lab stink of you and it's making me woozy, and-"

"Woah, woah, back up. The smell is making you woozy? How long has that been happening?"

"Not long. But long enough! Any time is long enough!" Zim gripped at Dib's collar, pulling him close enough for Dib to smell the sugar on his breath. He must have eaten something after being sick. "I demand that you fix it!"

"That's not a symptom humans deal with, I don't think," Dib said. "That's gotta be an irken thing."

"Pssh, that's ridiculous. Computer! Prove me right!"

"Actually, he has a point. Feeling more relaxed around the mate did happen in some of the older reports."

Dib grinned. "See?"

"That- no! You did this to try and lower my defenses- and you got the computer in on it too!" Zim's head darted around, frantic. His antennae were pressed flat against his head in nervousness, and when Dib reached for his shoulder, he scrambled back. "I said don't touch me!"

Dib's eyes were wide. "Zim?"

"I can't- you're just going to hurt us!" Sweat beaded on Zim's forehead, and he moved back again with a hand cupping over his stomach protectively- scooting all the way over the couch arm and hitting the floor.

"Woah, Zim, calm down!" Dib held up his hands. "I'm not going to hurt you, but you're acting really weird."

"You're acting weird, being all… grabby!"

"I'm not being all grabby. You're being all paranoid."

"You poisoned me, and you're- you're going to take the smeet and experiment on it, aren't you? You always wanted that, and now you- you-" Zim smacked at the floor, and a small trapdoor opened up, dropping him down into the lower base.

"Zim- goddammit, really? " Dib stared down the hole. "You better not hit your head! Computer, can you get me an elevator to wherever he ended up?"

"What's the magic word?"

"Now!"

"Hmmph. Doesn't sound very magic to me."

"Fine, please?"

"There we go." The couch turned over and Dib was dumped unceremoniously on his face on the elevator floor. It sped downwards as Dib struggled to stand up while it moved. It was fruitless anyways- as soon as they reached the lower level, the computer jolted to a stop with a loud "ARRIVED!" that just knocked Dib to his knees again. He gave a quick glare to the ceiling before running out.

"Zim? Come on, we need to figure out what's wrong!" Dib cupped his hands around his mouth to try and make his voice louder. He wandered for a good five minutes, nerves only winding tighter at each second that passed. If Zim did something stupid when he was freaked out like this and hurt the kid… Zim himself was a cockroach, Dib half-doubted anything could kill him, but the baby almost certainly was more vulnerable. "If you come out, I'll help you on your next experiment, whatever it is! As long as it's not dissecting puppies again, that was just gross." Dib peered into each room, looking for Zim but finding nothing. His head whipped around at a crash and a yelp from somewhere to his right, and he bolted for the direction of the sound.

"Oh, come on!" Dib jogged towards the voice- Zim sounded a little less freaked out now, maybe it was over? A light flickered on in a room to his left and he stuck his head in, to see-

Zim, huddled against the class that held the two remaining sharp-toothed weasels. One was poking at the other. There was a pile of equipment next to him that still had dust settling around it. "Really, Alexander, I thought you were the good one!" Zim muttered, glancing back at the tank. "Now I'll have to make more before I can release-"

Dib hurried over. "Zim?"

"What?" Zim looked up at him. "Have you come to mock me?"

"Not right now. You really freaked out up there." Dib sat down. "You okay?"

"Of course, why wouldn't I be?"

"Are you- are you serious? You looked ready to cram yourself into your safe room for a week. You're really fine?"

"That was ten minutes ago," Zim said. "I realized if you wanted to hurt me, you'd know far more effective ways than making me more comfortable around you to get my guard down. So I just locked you out of the weapons vault."

"...You have a weapons vault?"

Zim started laughing at that. "Oh, come on, every building should come with a weapons vault. You don't have one?"

Dib hugged his legs to his chest. "No, I don't. But I guess you're having weird snappy mood swings now, that's something that's going to be real fun."

"I am not! That was perfectly reasonable paranoia, considering you've tried to kill me before."

"I haven't in at least three years."

"Pssh, that's not that long."

"It is for me."

"That's because humans are dumb and their timing is dumb."

Dib sighed. "Right. Of course."

"Now, help me get rid of this weasel-ranha corpse before it starts stinking up the water."

Dib held out his hands, wondering when sentences like that stopped being strange to him.

If Zim switched between moods like this a lot, especially if they started getting more extreme, he was going to start bringing sweets to bribe him, and stuff for headaches.

He was going to need it.