"HORRIBLE STINK-BEAST!"

The little knife spun rapidly in the air before slamming right into the computer bank, shattering the main screen and erasing the image of the two Irken leaders laughing horribly as they watched the defect stagger. Colourful sparks spattered from the console, illuminating the two rivals. The small Irken screwed up his face in pain, bringing a hand up to touch the superficial cut that had been opened on his arm.

Dib froze – he had seen the thin, dark line open up and the green trickle that oozed from it. Blood, he thought, mind racing like an electric current through a lightning rod. He had seen Zim's blood, ACTUAL ALIEN blood. After three years. A simple 'drop in' on Zim's base had escalated to this – a fight in which one of them had actually drawn blood. Irken blood had a dark sheen to it. Fascinating. He'd love a sample…

He stopped this train of thought just in time to see Zim leap forward, spider-legs sliding out in perfect choreography, all gleaming and aimed at the same target. Dib yelled out in surprise and quickly gave ground before the slashing weapons as the alien began a beautiful series of lightning-fast strokes. Dib ducked, sidestepped and blocked the attacks as they came, keeping up with Zim's steady rhythm and all the while backing up. After three years of fighting, the two were perfectly in sync. They both knew the other's every trick; hell, they could pluck thoughts from the other's very mind. The Irken's ruby eyes were narrowed angrily. Oh yes, Zim had seen what the boy was thinking on seeing his superior Irken blood candies. And BOY, was he going to get it!

The teen was backed up against the wall of the lab, still desperately fighting off those dextrous appendages. Aha. That gleam in Zim's eye…he recognised that look anywhere. Self-righteous indignance. He smiled inwardly. Some things never changed.

Taking hold of a PAK leg, Dib wrenched it downward while bringing up his other fist to smack heartily into the alien's cheek. Zim reeled with a grunt, and that was when his foe surged forward with a holler of triumph. He'd lost his last weapon, but he had all the experience he needed for this fight.

But Zim was born from a military race – he may have been a defective, but he still had his training, and the reflexes of a cobra. In the blink of an eye, a single PAK leg shot forward to meet the boy. The sharp tip found Dib's midsection easily and the boy dropped to the floor, groaning.

That was definitely a cut on his side, but not a deep one. He wrapped an arm around the hurt area, wincing as he did so, but hoping he could get it covered up before Zim saw the blood seeping through his coat, he was glad it was black…

Too late, he'd seen. That expression on his face wasn't just interest, no, that was fixation. The alien met his human's eyes and his face broke into a devilish grin.

"Now we're even, Dib-worm."

Dib was relieved in spite of himself. Yes, now they were even. It was over.

And it was lucky that it had finished then, and not a few minutes later. Because now that Dib could pull his attention away from Zim, he noticed the heat in the room, and that acrid smell…

Zim's antennae shot up a second before the word 'FIRE!' left Dib's mouth.

They both looked up in horror. A spark in the computer bank must have ignited; the myriad cables and wires stretched across the base ceiling were smoking. Some were melting, and the room was filled with a bitter haze that stung the eyes and caused the walls to undulate.

Zim was already haring it for the exit.

"MOVE IT, STINK-MEAT!"

Dib didn't need t be told twice. Terror completely drowned his indignance at the insult, and it was all he could do to run after the fleeing alien. They had to make it to the elevator in time!

It took several heart-clenching minutes for him to realise he was lost. The horrible smoke was getting worse, the heat was intensifying every minute, and Zim was nowhere to be seen. Dib stumbled, coughing up soot. He raised his head and stared with smoke-blinded eyes into the chaos of noise and heat and falling debris.

"ZIM! WHERE ARE YOU?" His shout was lost as a huge groan shook the walls of the base. Dib screeched in terror as a huge chunk of the ceiling broke loose above him but somehow managed to force his limbs into action, flinging himself forward. He hit the floor, checked and scrambled forward, attempting to stand – and a pipe smashed right down across his legs.

The boy screamed as agony ripped right up through his spine. He was trapped. He was going to die here. There was no way any creature on Earth could move that pipe, and he was completely alone. Dib's breathing grew shaky as his body started to go lax. Oh, this smoke was awful. He couldn't breathe. The colours…such pretty colours….orange clashed with magenta and flecks of white, all overlayed with that smoky haze, and the fuzzy, welcoming darkness at the edge of his vision. His eyes began to slip closed. So.

And out of the flames appeared a lithe, dark figure, clothes shredded to pieces and burning. Dib's eyes flew open as he struggled to discern the apparition before him. It was his arch nemesis. Had the Irken come back for him? Or was he here to kill his rival himself?

Zim looked positively LIVID. His deep ruby eyes caught the orange blaze and danced with the colours, lighting them up in a hideous display of fire, and light and something white, and hot and simmering. Dib actually found himself cowering under that fierce, wild gaze. It was either pure desire to kill or some kind of sick possession. But totally foreign. Then a spider leg struck forward.

Dib felt the impact, sure it had gone straight through his back. He couldn't actually feel pain at this point thanks to the shock, but it MUST have skewered him. Then he felt the crushing weight lifted from his legs, and a gloved claw clamped down on the scruff of his neck, jerking him roughly out from under the pipe, and he found himself dangling haphazardly in the air and looking into the eyes of a small, very stubborn Irken. Zim was saving him! Without a word, Zim slung the boy unceremoniously over his shoulder and proceeded to carry him like a sack of dead kittens. If he wasn't injured, half-conscious and very bewildered, Dib would have murdered him.

Somehow they both made it to the elevator shaft – which was just that. A shaft. No elevator, and with a horrible sick feeling, Dib remembered that he'd disabled the elevator when he snuck into the base, using his own gear to get down the shaft - the same gear that was now lying in a charred heap in the corner.

Zim's eyes narrowed and he spat something in Irken that must have been a curse. His grip slackened on the boy and Dib slid down and looked up at the Irken's face.

"I…I'm sorry." he managed to whisper, "I guess this is my fault, huh?"

Zim glared at him, but it was softer than his normal glare.

"Yes, idiot. But Zim does not wish to end this…enemyship…now."

And Dib found himself smiling.

In one fluid motion, Zim snatched up the boy.

And threw him.

The teenager screamed as he rocketed up the shaft, the walls falling away at incredible speed. Suddenly he was sprawled on his back on the top floor of Zim's base, with the exit right in front of his face. Dib stared at it dubiously, but pride won over self-preservation and he wriggled onto his back to stare down the shaft at Zim.

"Come on!" he screeched.

Zim straightened up. Of course he wasn't going to die down here in his own base. His skin may have been fire resistant, but he could only survive so long in this nasty…burny…*ack!* heat.

Dib grew hopeful as the alien deployed his PAK legs, then baulked as he realised that there were only three. One of the lower appendages had snapped off at the first joint. Zim gritted his teeth as he looked at it, but resolutely plunged the three working legs forward. The hardened metal bit deep into the wall and the Irken began to climb. He had lost some of that fluid grace he had of four legs, but he was still a strong climber, with skill unmatched by any human. His race really was superior, Dib thought reluctantly. Sweat was visible on the Irken's forehead – he was tiring. And the walls of the shaft were beginning to look very unstable, buckling due to the heat.

The human watched helplessly was the alien began to lose his grip, sliding inch by inch down the wall as he groaned under the exertion.

That was when the top of the shaft gave way.

Dib shouted a warning, but it was too late for Zim.

His eyes became huge at the sight of his own base crumbling down on him. His gaze switched to Dib, and the human's heart leapt into his throat. The expression on Zim's face tore right through Dib. Gone was the bravado and stubbornness. This was a look of pure animal terror, a single sign that, yes, this was a LIVING CREATURE Dib was looking at. A living creature, a person, who was going to be killed.

Zim hung on grimly to the warped panel as heavy sharp, deadly debris thundered down past him. Dib drew in a breath. Maybe, just maybe, Zim could hold on?

And then that one piece of shrapnel came down last, and slid so smoothly into Zim's spine. There was a terrible noise, a metallic scraping as the deadly point sheared straight through one of the delicate cables that fixed the PAK onto Zim's back. His life support was destroyed. And in that one look the two rivals exchanged, they both knew that the other knew, this was the end for Zim. A shrill scream ripped itself from Dib's throat, mingling with Zim's as he fell to his final resting place. Dib saw the lights go out in the alien's eyes a second before he thudded to the floor. And then there was one heart-stopping image of the Irken's body, lying small and vulnerable and twisted on the floor, before the rest of the shaft caved in on top of him.

Dib dragged himself from the rapidly deteriorating base, his breath ragged and his eyes blinded by the tears that knifed down his cheeks. He barely heard the wail of the ambulance, or the pounding of feet and voices shouting if he was alright.

He didn't feel the hands that lifted him into the stretcher, or the dull thud of the ambulance doors slamming shut. It was all a blur of white noise and dizzy shapes that hung just outside his conscience, and the rest was just a black, sucking pit of mind-numbing…nothing.

There was only one truth in the world.

Zim was dead.