By the gods, people are actually reading this! Yeah, I'm surprised. (Not that I'm complaining, oh no...) Thank you all so much for you reviews! I hope you all enjoy, and please remember to review this chapter!

xxxxx

In Short Supply

Bell Curves

xxx

Approximate text adaptation of the memory records of Tallest Purple's Pak, four weeks ago at 170°130' Irken time, or approx. 6:30 pm: I've spent all day at the Primary Birthing Facility with a swarm of Technicians to check out all the machines and programs, but so far they can't find any errors in anything. Everything looks like it's running fine, which means the problem's either hidden really, really well, or some outside force is causing the genetic mixers to malfunction. This can't be random chance.

I mean, the statistics don't lie. Our species is changing and not for the better; how can it be good, when almost no Irkens with a normal height have been born in over 200 years? Huh? But Red and the Control Brains both told me not to worry about it, nothing's wrong. Okay, Red I can understand. He may be a good public speaker (fine, a GREAT public speaker, lucky bug), but he's not exactly the brightest Tallest we've ever had. We could use Miyuki back...

The Control Brains, though, that's just weird. They've got better access to the records of DNA mixes and Irken demographics than even I do, so shouldn't they realize that the random genetic mixers in the Birthing Facilities aren't random anymore? I figure they're glitched up, too; they can't possibly have recovered yet after that horrible trial with Zim. In fact, I'd probably be blaming Zim for all this, except the problem's been going on for twenty eras. Zim isn't anywhere near two hundred years old.

Red's not gonna help, and I've assigned my Technician swarm to check the Control Brains for any problems. Hells, I've even got a Vortian helping them out. But if they don't find anything, I'm just gonna have to solve this problem myself.

I really, REALLY don't want to think about how I'm going to do that.

xxx

It took the better part of the evening for Purple to convince Zim that he really was the Tallest. In the end, Zim insisted on pulling out an electron ruler to calculate Purple's exact height quotient before he was convinced.

"You're almost a fourth of a unit too tall," Zim said, frowning in puzzlement. "How can an imposter be taller than the Tallest?"

"That's because Red and I round our heights," Purple said wearily. "If someone asks our height it's a lot easier to say 217 units than to say 217.239046 units." Red's height was actually 217.240081 units, but potential Tallest were legally defined as the same height if they were within .1 units of the actual tallest Irken, luckily for Purple.

"Oh. Yeah," Zim said. He still looked baffled. Most Irken citizens were when they found out. Purple had experienced this enough times to know what Zim was thinking: you, the Almighty Tallest, would round your height down a fourth of a unit? You're so astoundingly tall that you can cut off some of your own height without losing any of your authority?

"Now do you believe me?" Purple asked.

"Yes, my Tallest," Zim said, and saluted. "My sincerest apologies! I merely had... difficulty believing that such a... eh... unusual request could come from you."

"You and me both," Purple said sourly. The chairs in Zim's base were too small for him, so he sat on a counter, and Zim apparently took this as permission to sit in a chair himself. "Keep this in mind, Zim. I wouldn't do this if I didn't have to. But Red doesn't believe me, and something's probably wrong with the Control Brains," Purple said. "I think there's a problem with the birthing facilities."

"I see," Zim said thoughtfully. "I agree fully, my Tallest."

"You do?" Could Zim actually have been observant enough to notice the strange changes in the Irken species? It was unlikely (very unlikely), but maybe being the shortest Irken to ever exist gave him a unique perspective on the empire's heights.

"I do," Zim said. "I myself have observed that most modern Irkens are a bunch of feeble weakling losers and not worthy of the empire. So, you must be planning to fix this by breeding smeets with the most superior genes possible, a mix between an Almighty Tallest and the greatest Irken to ever live. I understand now why you came to me for assistance." Zim beamed up at Purple.

Oh, for the love of Irk. "It's because you're so short," Purple snapped. He wasn't going to let this turn into another ego trip for Zim.

Zim visibly flinched. His head jerked back, shoulders hunched up, antennae flattened against his head, back hunched forward, slouching down in his chair. Hs smile changed to a grimace, his bright eyes dimmed in puzzlement and—hurt. Purple had never seen Zim look hurt before. Stupid, confused, angry, scared for his life... but never hurt. Zim said quietly, "Then... if that's what you wanted, my Tallest, you certainly chose the right..." He trailed off into incoherent mumbles.

May the Firmament teach Purple patience because he'd never be able to put up with Zim without it. "Look, do you want a super-secret special mission or not?"

"Of course I do!" Zim said brightly, straightening up and saluting, but something about his enthusiasm seemed off. "But if I may ask, my Tallest, why do you need an Irken... like me?"

Purple hesitated. "Er..." This would be a long explanation. Then again, he couldn't very well expect Zim to be contented with no explanation—stupid he was, easily satisfied he was not. "All right," he said, and took a small panel out of his Pak, a computer screen. "You can read bell curves, can't you?"

"Of course I can," Zim said proudly. "I do it all the time!"

"Fine," Purple said. He sincerely doubted that, but lit up the panel anyway. It displayed a normal-looking bell curve graph, a hill over a number line, with the peak of the hill directly over 100. "This was the height quotient distribution of Irkens four hundred years ago. Most Irkens were about 100 units tall, average height."

"Hmm." Zim nodded, leaning forward in his chair and studying the graph.

"The range of heights was between 80 and 120 units. Tallest Litchi was 137 units tall, and the shortest Irken on record was 66."

Zim nodded again, then frowned. "Only 137? Buy didn't you say that you're—"

"Yes, Zim, I'm getting to that," Purple interrupted before Zim could start singing praises to his and Red's superior heights. "This is a graph of the height distribution today."

The display on the panel changed. Zim's antennae stood up. "Is there... something wrong with that?" he asked. Purple understood why he was baffled.

"Nope. It's correct."

On the bell curve, the hill over 100 units had collapsed down to nothing, and there were two new ones: one hill over 70 units, another over 130, marking the average heights of modern Irkens. While the original graph had extended between 50 units for the shortest Irkens and 150 units for the tallest, this one ended below 0 and over 200.

"There are almost no Irkens with heights between 90 and 110 units. None," Purple said. "That used to be average height. Most Irkens today are either between 40 and 80, or between 120 and 160—nothing in between. The Tallest, Red and I, are 217 units, and the shortest Irken alive is negative 12. Which means the empire—"

He was cut off by a horrified screech. "I-I'm a negative height?!" Zim wailed. "But how?"

Purple rolled his eyes. "Calm down, Zim," he said. "This height curve graph isn't based on a single unit, it's a measure of how close an Irken is to average height. It just wasn't calculated to measure someone as short as you, that's all. Okay?"

Another wail. Zim squeezed his eyes shut and pulled at his antennae in aggravation. "First the roller coaster and now this?!" he said, curling up in a ball on his seat. "I'm the only negative Irken in the universe!"

Roller coaster? What was that? "Open your eyes, you're going to suffocate yourself like that," Purple said. "No, you're not the only negative Irken, okay? I think Skoodge is a negative 3."

Zim quieted and peeked up at Purple. "Twelve is a bigger number than three, isn't it?" he said hopefully.

Sometimes, Purple really had to wonder what sort of insane logic Zim functioned on. "If it makes you feel better."

"All right!" Zim flashed one of his typical megalomaniacal smiles, then grabbed Purple's panel to study the graph. "So what's wrong with this?" he asked. "Taller Tallest are good, right? And shorter Irkens are just more inferior fools to become Labor Drones for us superior Irkens to boss around."

Says the Irken who, if there were any justice in the Firmament, should have been a Drone himself. "Well, yeah, taller Tallest ARE good. Especially for me," Purple said. "But all this isn't good for the whole empire." He pointed at the valley in the graph over 100 units. "See that? Know what that is?"

Zim stared at the graph. "The bell curve thingy?" he offered.

Purple groaned. "No, Zim, I meant that dip in the curve. That is what the evolution of a species looks like."

"Really? Doesn't evolution mean we get wings?" Zim asked eagerly. At Purple's blank look, he said, "Y'know, really thin ones? Not like bird wings, those are ugly."

"No, Zim."

"What?! I thought we were gonna get wings!"

"No!" Purple shut his eyes and counted to ten. He could really use a snack right now. "Zim. Listen. There are several ways a species evolves. On is by getting split in half," he said as patiently as possible. "And then half of the species, as it breeds, will change. Say, it gets a new eye color. Or really big teeth. And since both halves of the species are evolving separately, a bell curve comparing the new teeth sizes to the old teeth sizes," he pointed at his panel, "will look like this. Because half the species is evolving one way, and half is evolving another. This is what happens when a species splits in half. Get it so far?"

Zim nodded slowly. "So, this chart thingy shows Irken teeth size..."

"No! It's STILL HEIGHT! You stupid little..." Purple had to forcibly resist the urge to wring Zim by the neck. He turned around so he wouldn't have to actually look at the diminutive defective exile. "Why did I think this would work? Huh? Why?! Stupid plan, Pur. Stupid, stupid plan!"

There was an awkward silence. "Do you... want something to eat?" Zim asked tentatively. "I have snacks."

Purple nodded tiredly. "Yeah, why not?"

xxx

It took three candy bars and two jumbo bags of chips before Purple calmed down enough to actually talk to Zim again. "How did you get this stuff, anyway?" he asked, looking at the empty bags and wrappers, stamped with the Irken corporate logo. He and Red sure hadn't been shipping Zim supplies; they'd thought all this time that he was surviving on Earthen weeds and sticks or something.

"I ordered it from Callnowia," Zim said. He was sitting across the table, trying to shake the crumbs out of the two chip bags Purple had finished.

"All your food?" Purple said, stunned. "For two years? But you were fined for every money you had after Operation Impending Doom I. You should be broke!"

"Is that what happened? I always knew there'd been some sort of mistake," Zim said cheerfully. "Anyway, until I get my own monies back, I make some spare monies from Earthen exports."

This was news to Purple. "Earthen exports? What kind of exports?"

"Mostly tanks of hydroxylic acid."

Purple choked on part of his fourth candy bar. "Wh-what?! You've been sending huge tanks of water into the Irken Empire?! Do you have any idea how closely we monitor the distribution of hydroxylic acid?"

"Yeah, that's why they pay me a lot," Zim said proudly. He seemed completely oblivious to the fact that he had become a smuggler of the most dangerous black market good in the Irken Empire. Where could he possibly get water on such a backwards planet as Earth, anyway?

No. Purple could deal with that later. (Probably the next time an alien assassin went after him and Red with a bucket of water, courtesy of Earthen exports.) For now, he had other issues to deal with. "Anyway, Zim. Do you get what I was trying to show you with the graphs now?"

"Of course," Zim said, as if it were obvious all along. "The empire is splitting in two. That's bad."

"Yes, Zim, that's very bad," Purple said, hoping he sounded more helpful than sarcastic. How to explain the next part, the reason he had come to Earth in the first place...

"But there's one thing I don't quite get, my Tallest," Zim said. "You said this evolvy thing happens when a species splits in half and they can't reach each other, right? That would never happen on Irk."

For once, Zim was right. With every Irken alive born in the smeet birthing facilities, and the Control Brains carefully ensuring that all genetic mixes were perfectly random, there should have been no way the Irken race evolved at all, much less started evolving into two, separate species.

The mere thought sent chills along Purple's antennae. The proud Irken race, literally and irreparably torn apart... It was every Tallest's nightmare, that millions of years in the future, every time a newborn smeet's Pak received its programming, they would learn that he was the Tallest who had let ruin fall upon the empire.

"I don't get it either," Purple said. "It shouldn't be happening, but it is."

"You should check the birth thingy," Zim said.

"The birthing facilities. And I did."

"Oh." Zim put on a thoughtful expression for a moment. "Hah! I've got it! Maybe all the average height Irkens are stupid and keep dying!"

Purple stared at Zim. "No."

Zim cackled. "I knew it!"

"I said NO, Zim!"

"Oh. Are you sure?"

"Yes. I'm sure." Purple glanced at the table and realized that all the snacks were gone. He sighed. This just had to get harder, didn't it?

"Look. I'll say this one more time: I'm not here to just talk to you, and I don't want you to help figure out what's gone wrong. You're just going to do what I say so I can fix it," Purple said. "Red doesn't believe me, nobody can find a problem with the birthing facilities, and I think it'll be too late to fix anything unless I act now." He looked at the empty candy wrappers to avoid looking at Zim. "That's where you come in."

There was an uncomfortable silence. "Yeah, I still don't see why all this means that I have to... do all that... stuff," Zim said. "With the carrying-your-eggs thing."

"Think about it," Purple said. "I'm 217 units tall, you're -12. We're at the extreme ends of Irken height. But, if you averaged our heights together, they would be..."

"Almost exactly 100 units," Zim said, his eyes brightening with understanding—a first, Purple was sure.

"Yeah, 100 units. Which is the height my empire needs more of."

Slowly, a look of pure horror crossed Zim's face. "Wait—how many smeets do we need to make?"

Purple thought of his bell curves, and envisioned the hill over 100 units on the first graph as a giant pile of smeets—and then as a very big ditch in the second graph. It would take a whole lot of smeets to fill that ditch in and make it a hill again. Millions. Billions. "Hopefully, I can figure out the problem before then."

Zim nodded weakly. "I have... complete faith in you, my Tallest," he said, with absolutely no faith in his voice.

Purple pushed back his chair and stood up, glanced around the strange kitchen—he didn't know much about Earthen culture, but Zim seemed to have done a surprisingly good job creating a convincingly disguised base, especially with that "Earth food rocks" poster. He wondered whether or not Zim might have been a good Invader after all. If, y'know, he didn't have a super-defective Pak. "So," he said, as Zim started to stand. "We've got to get this over with sooner or later. Let's go get you the surgery you'll need."

Zim fell out of his chair. "Surgery? I agreed to none of your surgery!" he said. "What kind of surgery could Zim possibly need?"

"What kind of surgery do you think you need? Did you expect to lay an egg out your anus?" Purple snapped. "That's just stupid."

"But Irkens don't have anu—"

"I know, Zim," Purple said. "Irkens don't have genitalia, either. At least, we're not born with them. Do you have a med bay?"

"But what do genitalia have to—"

"MED BAY!"

"Eh..." Zim pointed into the living room. "There's a lift under the sofa."

Purple swept past Zim and into the living room. (The effect would have been much more dramatic if he had come to this planet with his hover-belt... Oh, well.) "Computer? The lift."

"Yes sir, Almighty Tallest Purple."

Zim walked up beside Purple, muttering to the computer, "You never show me that kind of respect..." He cleared his throat. "My Tallest, I don't think all of this is necessary. I'm sure I can handle anything you need of me without doing anything... strange to my body."

Purple wondered why Zim was making such a big deal over this; he didn't even know what he was supposed to do yet. "Irkens haven't reproduced naturally in millennia, Zim. This whole thing is strange," he said, as they both got on the lift. As it lowered, the sofa fell back in place over their heads. "We both need to do some weird stuff to our bodies." Purple had already gotten surgery. Not that he intended to tell Zim all the details.

"But—my apologies, my Tallest, but it sounds as if you expect me to become a layer," Zim said. "Which is just... hideously stupid! I mean, that's impossible, isn't it?"

"No, not impossible. Just... very painful."

Zim's eyes got so wide that Purple was afraid he'd start hyperventilating. "No!" he said, shaking his head. He crossed his arms over his torso and backed against a wall of the lift. "Never! You can't make me! I refuse to go through with this!"

Oh hells above, why did Zim have to be the shortest Irken alive?! Skoodge was obedient and he'd been -14 units before his final growth spurt. Why couldn't it have been Skoodge? "Why not, Zim?" Purple said wearily. He'd just about had it with this nonsense.

"Because then I'll have to be a girl!" Zim said. "Like TAK!"

"Oh, come on! That's the dumbest—"

"I don't care!" Zim scowled furiously at Purple. "You forget that there is one and ONLY one Zim! ME! And I refuse to be anything that is NOT me! Not an Inventor, not a Frycook, not a failure, and not a layer!"

The lift stopped, the wall behind Zim slid back, and he shot four metal legs out of his Pak and tore away from Purple. In only a few seconds he was out of sight.

"Zim? ZIM! Get back here!" Purple ordered. What could drag him out? "I'll give you a snack from Sintillia!" Nothing. That worked on most Irkens.

"Computer, stop him," he said, walking out of the lift and looking back and forth. Most of the lights in the subterranean levels of Zim's base were dimmed or off to conserve power; that also made it easier for Zim to hide.

"What, are you joking? With all due respect, Almighty Tallest, he'd totally kill me," the computer said.

"Fine! Worthless," Purple snapped. He really wouldn't mind letting Zim run off and hide. If Purple never saw Zim again in his life, he could die happy.

And yet... he couldn't do this alone. As much as he loathed to admit it, Purple needed someone to help him pull this plan off, someone very short, and Zim was the best candidate for the job. He had to get Zim's help.

There had to be something he could say to get the stupid little defect to show himself. It was no wonder Zim had gotten himself banished...

That was it! "Zim," Purple shouted. "I thought you wanted to be a hero for the Irken Empire!"

There wasn't a sound. Purple hoped Zim was still listening. "This is your best chance. Think how much the empire would love you if you were able to help save the Irken race. And you're the only one who can do it, Zim. The fate of the empire rests on you."

That, Purple thought, was the most brilliant load of dookie he had ever come up with.

And Zim bought every word. Within a few seconds, Zim emerged from the gloomy corridor he'd run down, head held high with pride. "I'd gladly serve my Tallest," he said, saluting smartly. "Even if I do have to become a girl."

"Good," Purple said, relieved that disaster had been averted. "So which way's the med bay?"

"This way, my Tallest," Zim said, and led Purple down another pathway.

"Anyway," Purple said, "you're not actually going to be a girl, Zim. I mean... really, you're not girly at all. You're just going to be a layer. Lay eggs and stuff. That doesn't mean you have to curl your antennae or anything." Irkens had been sterile for so long that they no longer associated their gender—girly or boyish—with any sort of physical sex; only the actual genes. If the entire empire woke up the next day with genitalia, completely randomly assigned, it wouldn't affect their sense of self-identity—and a male Irken who woke up with layer genitalia wouldn't be any less male for it. Just a male that could lay eggs.

"Oh. Good." Zim pressed his palm against a wall panel to open a door marked "MED BAY," then turned to look oddly at Purple before he stepped through. "Hey, if I'm the layer, then that means you're the fertilizer. Right?"

"Yeah?" Purple said.

"So that means," Zim continued, "to make an egg, we're going to have to da—"

"Shut up," Purple said. He didn't want to hear about it until he absolutely had to.

Zim's face lit up like he had just been handed a one-way ticket to Purechocolatia. "Of course, my Tallest!" He ran into the med bay, grinning crazily. "What are you waiting for?!" he bellowed at the computer. "Do the surgery thingy!"

"But I don't know how."

"Make something up! HURRY!"

Purple hadn't expected such a sudden change. Zim wasn't reluctant at all anymore. Exactly how long had it been since the guy had got a dance, anyway? Considering his height and his reputation, Purple wouldn't have been surprised if he'd never danced before. Zim would have stopped looking attractive once they'd completed their training under the surface of Irk, once everyone was a full head taller than him... Purple almost found himself pitying Zim.

Almost.

"Computer, analyze and execute this program," Purple said, pulling a disk out of his Pak and holding it up for the nearest computer modem to scan. It had taken him a week to track down two of these, one for layers and one for fertilizers: ancient files that had been used by medical robots to do genital reassignment surgery, years before Irkens had lost their sexes all together.

"Analyzing... gimme a sec..." The computer hummed to itself for a few seconds. "Done! Executing program."

No less than twenty medical tools on long metallic arms popped from panels all over the room, a ridiculously wide variety of blades, scalpels, saws, needles, and wrenches; one arm snatched Zim up, shoved him onto an operation table, and fastened him down with three steel straps. All the eagerness fled from Zim's face. "M-my Tallest?"

"Good work, Zim. You're doing your empire proud!" Purple said, tapping the panel to open the door and backing out of the med bay. The door was almost shut when the screaming started.

Purple was glad that much was over. He'd known from the start that getting Zim this far would be like jumping in a pool of boiling water, but that didn't make it any easier.

The surgery to give Zim all the necessary organs and external structures would take at least 30°, plus another 10 to 20° to let him recover—a little over five "hours" by the Earthen measurement of time, if Purple had done his research right; it was always good to understand the planet you were on—so Purple had some time to waste. He made his way upstairs, tried to figure out how to turn on the big human screen in the living room (a teevy, Zim had called it, right?), ran into Zim's defective SIR unit, and spent at least ten minutes listening to it tell a story and wondering what on Irk it was talking about.

He was quite fine with listening to the defective SIR. He was quite happy with doing anything, really, other than think about what he'd have to do once Zim had recovered.

If his little visit with Zim had been a dip in a pool up until this point, the next part would be like swimming across an ocean of hydroxylic acid.

xxxxx