"Dr. Cain?"

"Douglas," the human replied with some surprise. "What's on your mind?"

"I've been meaning to ask you this for a while," the mechanic said. "Did you have any idea Sigma would become… what he is?"

"You mean a genocide-minded monster? You don't have to tread lightly with me, Douglas."

"Well, there it is, then," Douglas said uncomfortably. "I'm just curious if there was any… indication. Any precursor."

"Thinking like a mechanic, eh?"

Douglas nodded. "When I look at machinery, I can see fatigue and wear and know that a component is losing integrity. It's not perfect—sometimes a standard-looking part can give on you without warning if it's exposed to new conditions—but it's pretty reliable. What about Sigma?"

"Parts aren't people."

"I know that," Douglas said defensively. "I'm not so awkward that I haven't noticed that. I just thought… you know, since he's a reploid… maybe there was some way to tell?"

"But that's just it," Dr. Cain said. "I'm sure there have been reploids who've gone Maverick because of some flaw in their systems. Sigma just isn't one of those. His core was perfect, right from the beginning. That's why I named him that, did you know? Sigma is the unit for standard deviation. All throughout the construction and initialization phases, every single one of his parameters fell right in the middle of the acceptable values. Not a one was even a single sigma out."

"He's the best of us, huh?" said Douglas.

His tone of voice, more than his words, annoyed Dr. Cain. The roboticist shook his head. "Don't go thinking that perfect construction means perfect being. Nothing could be further from the truth. No human ever got away with a crime by blaming his genes. That's the whole point of reploids—that they choose their own fates. I've had the devil's own time convincing people of that fact, especially when X himself became such a paragon. 'It's because he was built by Dr. Light, that's why he's so perfect!' Bah. X could just as easily have become a Maverick, just as Sigma could have remained a loyal Hunter. Things just didn't… turn out."

Douglas was momentarily at a loss. He searched for something to say—until he glimpsed something in Dr. Cain's face. The human was looking beyond Douglas. "Now that I think of it," he said in vacant tones, "he did ask me something, once. I was talking about the capabilities he'd been endowed with. He listened attentively for a while, but then he cut me off. He asked me, 'Am I just a doll to you?' 'Never,' I told him. 'Never to me.' 'But to others?' 'Perhaps,' I answered, 'but they're wrong.'"

Dr. Cain huffed. "I guess he didn't believe me, eh? Not that I think it would have made too much difference," he added hastily. "Conversations like that aren't defining moments, and he didn't become a Maverick for a long time after that. Still… I have wondered, at times…"

Douglas shifted anxiously. "I guess that's something I'll never experience," he said. "I'll never have that level of personal investment in another being. I can't imagine what it must be like. When I fix or build something, I have lots of confidence in what it's going to do. I know how it'll perform because I know how I built it. You, on the other hand…"

"Anything could happen. And we have to take the bad with the good. Tanstaafl."

"Tan—huh?"

"There ain't no such thing as a free lunch."

"…that's a double negative."

"That's humanity for you. Our wisdom and our foolishness are inextricably linked."

The pensive expression returned to Dr. Cain's face. Douglas tried to put himself in the human's position. "Have you ever wondered if… if Sigma might change his mind? If he might… repent, I guess? I mean, if we can get Zero back, we want to. Even after all he's done—which hasn't really been that much. So if Zero says he's sorry, maybe does some things to prove he's sincere, he could be a Hunter again. Right?"

"That's for other people than us to decide."

"I don't see why he couldn't," Douglas said. "So, if he can come back… have you ever tried talking to Sigma? You're like his father, after all, you made him personally. That has to mean something."

"I assure you, it's irrelevant to him. He's the one who declared war on me. Us," he amended quickly.

Douglas noticed the misstep and didn't press on it. "I suppose it's impossible at this point, after all he's done. Way too many crimes, way too many wars, way too much… everything. There comes a point when you can't repair something no matter how much you try. I know that, but… I think I see in you… that you wish you could."

Dr. Cain gave the smallest of chuckles. "Don't ever grow old, Douglas. You get regretful. I never was, when I was younger. I can feel the bite of it now though. And yet, at the same time, I know it never would have worked. He would have killed me for even trying. Because once he made up his mind, compromise became impossible."

"Impossible? That's a strong word."

"But apt. To a certain point of view, compromise is weakness. If ever Sigma has been consistent about something, it's that he can't stand weakness. Imperfection offends him. At this point in his life, he only knows one way to deal with weakness."

Dr. Cain drew a single finger across his throat.

Sigma stepped away from the construction gantry. There had been capacity here for building the largest robots, capacity just waiting for a new master with vision enough to use it. He'd had to modernize some of the equipment, but it had served its purpose nicely. He flexed his hands. The feeling of power was glorious.

This new body was, in appearance, quite similar to his old. It was humanoid, bore his usual face, boasted broad shoulders, and was round with prominent pseudomuscles in the abdomen. The most obvious difference was size. Sigma was now a titan of his own making. His hands were large enough to hold X's entire body, arms, legs, and all. He indulged in a feral grin. That was a good idea, wasn't it? To leave X's head exposed while he squeezed his body. The screaming would be delicious…

The elevator announced X's arrival. Sigma took another step forward. The ground shook. His head nearly scraped the ceiling.

Sigma would enjoy this.

The elevator announced to X that he had arrived. He took a moment to assess the situation. His self-repair had been very busy and had made at least rudimentary fixes to most systems. The cost was that he was running somewhat low on energy. He had enough for weapons and movement, provided the battle didn't go for long, but there was nothing left to spare for repairs. Any additional damage was likely to be semi-permanent.

He'd made no effort to try and repair the like-flesh on his face. He didn't have the proper materials in any event. It left his visage gruesome, he admitted, but there were times and places to worry about that. This was neither the time nor the place.

Sigma wouldn't care how he looked.

He nodded to himself. "I've got to settle the score. One… last… time."

He stepped through the elevator and looked over his foe. One thing you could always say for Sigma—he was never hard to find.

"Ho-ho! Do you like it, X? Doesn't it fill you with awe?" The voice boomed out from a vocal processor sized to the same dimensions as the rest of him. The giant couldn't fully extend its arms to the side, it took up so much of the room.

X scratched his head. "How were you planning to get out from underground with a body like that?"

"Details, details. I'll smash my way out! I don't care what obstacle is in my way. This body is totally invincible. No weapon can penetrate its armor. And with this much firepower, I can defeat any number of enemies that might try to stop me. It's game over, X!"

Sigma extended his hands forwards. "Die, insect!"

From his fingertips, bolts of power raced towards X's location. Each one had been carefully calibrated as a result of Sigma's obsessive research. A direct hit would be able to punch through X's armor and gut his internal systems. They made a mess of the floor when they hit, sublimating some of the metal and sending fountains of dirt into the air. This was more than just aesthetically pleasing; each shot made the arena smaller and cut off more of X's space to maneuver.

These spectacular pyrotechnics almost resulted in Sigma losing track of X's location. The Hunter had dashed forward to avoid and retaliated with a charged shot to Sigma's leg. The impact didn't even register with Sigma, nor did a second shot into one of Sigma's palms.

Sigma could hardly restrain his glee. This body was magnificent! He was impervious to X's attacks, leaving him with the luxury to give the Hunter a fitting demise. He moved his hands out of the way so that his head had an unobstructed view of X. The gem on Sigma's forehead whined for a moment. The broad blast of energy that followed would have turned a city bus into ash and slag.

This time, Sigma did lose track of X. Only for a moment—and when the moment ended, he saw X pushing off from the wall at the same height as Sigma's head. Sigma brought a hand up to swat the puny robot. X's motions were impossibly quick. He used the encroaching hand as another surface to jump from, rebounded off the wall, and sprang at Sigma's face even faster than before.

The charged shot that hit Sigma's forehead jewel was an unexpected and loathsome surprise. But it didn't hurt him, and it wouldn't for a while. Sigma had done the math and knew it would take fifteen more shots like that to get through—an impossible demand against a body such as this. He saw where X was going to land, charged the jewel again, and unleashed another broad-area blast.

When X reappeared in Sigma's vision, he was in a different area altogether. Sigma's analysis subroutine was at a loss to explain how the robot had dodged an attack that took up almost the whole area of the floor.

Sigma had programmed extra algorithms into his targeting system. His database of X's battles was extensive, and the algorithms were supposed to use that data to refine his targeting system's solutions. They weren't working or the Hunter would have been garbage by now. Angrily, Sigma disabled them.

It didn't matter, not when X couldn't hurt him. All it did was delay the inevitable. Sigma took a shallow step back for extra space and let fly with both hands, one finger after another, a sustained barrage to corner and annihilate the Hunter. X dodged back and forth, back and forth, avoiding the new craters that Sigma was creating. To Sigma's growing irritation, he seemed to be getting faster with every dash. No matter. He would run out of floor soon. To speed it along, Sigma powered up his gem for another go. X might be able to dance, sure, but to avoid an attack like this…

X cut a path through the dust and flame, leaving silhouettes from his passage. Before Sigma could retarget, the Hunter leapt up and landed on the back of Sigma's hand. Sigma turned his hand over to flip X off, but the Hunter was already airborne. Sigma didn't have time to smile, though he wanted to. With X suspended in air, surely now there was no way the jewel could miss—

Except that X's shot came in first and cracked the weapon's jeweled front end. Automatic safeties cut in to cancel the shot and drain power from the weapon. Two shots! X's weapons were so primitive it should have taken fourteen more after that one! Sigma, furious, flailed at X with both hands. The blows buffeted the blue speck but never connected with any real pressure, as if he were a large blue gnat. X touched lightly on the ground. Sigma let fly another stream of attacks from his hands. He could repair the jewel, just give him a little time, just…

And now X was moving so fast Sigma had trouble following him. The blur of blue leapt between Sigma's arms. Sigma reflexively rotated them so X couldn't land. X didn't mean to. He ricocheted from one to the other, bouncing back and forth like a pinball. When he reached the shoulders, he landed briefly on Sigma's collar before leaping in front of his face. Another charged shot—Sigma's sensors briefly registered that it had the highest output yet—tore through the forehead jewel and annihilated the weapon inside.

Sigma staggered backwards as X fell the long distance back down to earth. Sigma tried to kick him, but the motion was doomed before it even began.

How could this be happening?

"What's going on, X?" Sigma demanded. "I've watched your battle performances very carefully, and I've gone over your specs in great detail. I know exactly what you're capable of doing. That's how I designed this armor—specifically to beat you! What trickery is this?"

"There's no trick," X answered in conversational tones. "Just an act of will. Sigma, do you know why our designers give us limits? Engineering-wise, I mean. There are a couple of reasons. Sometimes it's a hard limit—more stress than this, and a component gives. But those are rare. Most limits are because the components have a range where they may or may not break. You're guaranteed to get good performance up to a point, and beyond that you're taking ever-greater risks. And some limits are to prevent long-term failure. You're not supposed to cross a limit because it'll wear the part out faster, or it'll put extra stress on the rest of the system."

Sigma's self-repair system reported that the forehead jewel was irreparable. Sigma could deal with that. It was unfortunate, but X couldn't inflict any more damage that way; the weapon was back-stopped by more armor, so Sigma's all-important processors would be safe. Still, to think the insect had harmed him, even a little…

"Well, thanks to you and Zero, I've spent five wars finding just where my limits are. I've explored them and discovered which ones are there for which purposes. I'm now in total control of my body. I know my true capabilities. They're not what my schematics say they are. They're what I say they are!"

X seemed to grow brighter in Sigma's vision. The jewel on X's forehead was pulsing rapidly. Sigma detected an unprecedented amount of energy emanating from the Hunter, as if his power distribution system was letting his whole reserve go at once. Sigma felt an unwelcome thrill of fear.

"Fighting Zero was hard. That was a test of conviction. Fighting you is a test of strength. That's easy. You made a big mistake, this time. You assumed that my capabilities were fixed. I am X, Sigma! I am variable! You have no idea just how powerful I really am. Here's a taste."

With a snarl, Sigma pointed his hands at X again. He never got the chance to fire. This time X was so fast his motions barely registered in Sigma's optics. Sigma stumbled as he tried to follow X's path, but the Hunter was already behind him. A leap, a bounce from a wall, and X was level with the back of Sigma's knee.

"You've committed a lot of crimes, Sigma. It's time to start paying for them. This one's for Eurasia!"

The back of Sigma's knee was not solid armor—it couldn't be and be flexible as a joint needs to be. It was segmented to allow for more natural motion. X's targeting system focused with impossible accuracy on the miniscule gap between segments. The buster was too large a tool for this. Most of the blast would be deflected by armor. The F-Laser, on the other hand, focused all of its cutting power onto the exact location X wanted to hit. A crack appeared in Sigma's defenses—small, but real.

"This one's for Repliforce!"

X fired his boosters to dash forward and punched in with the Frost Tower. There was precious little moisture in the air here, but what there was accumulated around X's fist like a spike. X drove that spike into the chink he'd made with the F-Laser.

There was no way the ice was hard enough to penetrate armor. It didn't need to be. The real weapon was the cold itself. Sigma's armor cooled rapidly, contracting and becoming brittle; the sudden change in temperature from burning hot to freezing cold caused the metal to experience thermal shock. The crack from the F-Laser rapidly expanded as the armor split apart. The gash was now visible.

"This one's for Dopplertown!"

X recoiled backwards from his hit. A boost kept him airborne and at the right height. He was running critically low on raw resources to make projectiles, but he could spare enough for a Tunneling Missile. The tip of the missile plunged into the gap in Sigma's armor. The brittle armor surrounding the chink cracked and shattered. For almost two seconds the missile bored deeper and deeper and deeper into the gap, wedging itself close to Sigma's vitals. When it exploded on its timer, the internal components of Sigma's knee were left exposed and unprotected.

"This one's for your evils against reploids!"

Recoil from the missile had knocked X back towards the wall. He sprang from it again, mostly upwards, putting him back in firing position. The Sonic Slicer made mincemeat of vulnerable wires and internal structures. Sigma's knee buckled as it was hollowed out.

"This one's for all the humans you've hurt!"

X hurled himself forward with yet another boost even as his legs screamed at the torture he was putting them through. When he made contact, the Electric Spark fried every electrical system between Sigma's heel and his hip. It happened so fast there was no hope that Sigma could remain standing. Internal systems braced for impact as his balance vanished.

The colossus toppled backwards, smashing to the ground on its back. X, of course, avoided the fall completely, and ended up in the air directly above Sigma's head. Fear swept over Sigma's face—and fear on a face that large is highly visible.

"This one's for Zero!"

X had used this weapon exactly once, and it had inflicted so much damage on his own systems he'd sworn never to use it again, but what the hell. His left arm wouldn't be able to handle it, so he reproduced Zero's beam saber with his right arm alone. Sigma raised his hands to protect himself. X copied and modified the move Zero had used on him—a half somersault followed by a boost to create a vertical down-dive. X shot between Sigma's hands before they could close on him.

He buried the beam saber in Sigma's eye. Down, down, down he drilled, through screaming metal and vaporized plastics and burning insulation and wildly sparking electrics. With all of his power and weight behind him, he forced the saber so deeply into Sigma's skull that he connected with vital processors.

Sigma screamed as X began to kill his brain.

X's arms were never supposed to support that much output. He pushed himself until his arm's circuitry threatened to burn up before he turned off the saber. He sprang off of Sigma's face. It lolled lifelessly in X's direction. Sigma's arms dropped to his sides. Cacophony ruled for a moment as tons of metal crashed and banged. X waited for the reverberations to die down. His gaze never left the muscle-bound giant.

Sigma's functioning eye was focused solely on X. X knew he had Sigma's complete attention. "There's one more," X said softly. "You've put me through five wars' worth of misery and pain. Revenge is a nasty thing, and on the whole I think it's beneath me, but just this once, I'll indulge myself.

"So here's one more, Sigma. This one's for me."

"Heh heh… you really are the pride of the Hunters," Sigma replied. "Somehow you've even beaten this magnificent body. But it doesn't matter. I will never die. I'll just come back again and again. As long as reploids and humans are killing each other, I will always have a place in this world."

"Which is why I will kill you now," X said. "I will build a world of peace with my own hands. You have no place there. It's time for you to die."

Sigma's functioning eye rolled back in its socket—then snapped back to X. "What have you done?!" he screamed.

"You weren't always this careless, Sigma," X said. "You cheated death often enough that you convinced yourself you were immortal. That made you complacent. What do you think I was doing up there in that command room? Hiding? Playing for time? I was cutting off the base's lines of communication. I left you nothing to tap into. And you can't use that body's transmitters either. Remember, this was a hidden base for Dr. Wily. It was supposed to never be found. It's impervious to any signal of any kind. You've got no way to transmit your persona out of that body. You're trapped in it."

X advanced slowly on his enemy. "There will be no escape, this time. There's no fallback base or reserve body. Nowhere to run. This time, you die for real."

Sigma's face showed that he appreciated the prospect for the first time. He did not take it gracefully. "Now hold on, X," he protested vainly. "We can be reasonable about this. You can't kill me! I surrender!"

"Funny thing, but I'm not taking prisoners today."

"You have to take me into custody, don't you? So that there can be a trial!"

"No, I think the facts in this case are fairly well-known."

"Your conscience won't let you kill someone who's unarmed."

There was something very nearly approaching hate, barely contained in X's voice, when he replied, "Don't you dare tell me about my conscience. Come on, Sigma. I thought you were made of sterner stuff. All the other times we fought you had nothing but contempt for me. You were awfully brave when you knew you couldn't die. It's amazing what changes when death is real."

"Wait! Don't you believe in mercy?!"

X stopped still. "As a matter of fact, I do," he said.

Sigma was suspended. For a moment, he dared to hope.

X raised his arm. "But not for you," he added.

The charged shot went into Sigma's skull through the hole made by the saber.

Sigma's body went dead. All signs of life vanished.

The fight was over.

Zero listened most attentively to all that was said. He struggled to move and he couldn't fight, but his hearing was working just fine.

Oh, no! Surely X realized…?

Next time: Finale- Rebirth