Dib got on the bus, plopping down in one of the middle row seats with a sigh.

The Skool had sent the kids on another field trip, to who-knows-where.

Dib wasn't sure if this was another one of Zim's plans or if it was the real thing, but either way he was weirdly excited about it. Beats sitting in a classroom all day listening to Ms. Bitters drone on and on about everyone having 'miserable lives' and that they were 'destined to die in a ball of fire.' and blah blah blah.

The other kids started filing onboard soon after Dib sat down, they were talking and laughing and just being regular kids for now.

Torque flicked Dib's forehead as they passed him. "What a dork," he said, laughing loudly in passing as he joined the rest of his friends near the back of the bus.

Then Zim walked up the steps and onto the bus, stopping at the top and scanning the rows of children slowly.

He looked…odd. Like he was on some kind of drug or something, but Dib didn't know if that was the case or not.

Whatever the reason for the strange behavior, Zim sat down in the third row of seats and stared out the window, keeping to himself for now.

Dib didn't like it. Something had to be up with the alien.

"What are you up to, Zim??" Dib demanded as he got up from his seat and walked up to the alien. "I know you have something to do with this."

Zim's antenna twitched and he slowly looked at Dib. He was in his disguise, but the look he gave him was weird.

"Do you ever get tired of asking that, Dib-thing?" He questioned in a weird tone. "Maybe you should think of something more unique."

Dib was taken aback. "Why would you ask that, Zim? Is this part of your next evil plan?"

Zim sighed and shook his head, turning back to the window.

"What's up with you today?" Dib asked suspiciously. "You're not your usual loud annoying self."

"I am as I've always been," Zim muttered, looking at Dib briefly. "Now I would like to be left alone."

"Why, so you can continue to work on your plan, whatever it is this time?" Dib said, leaning close to the alien. "I'm on to you, Zim! I'll figure out what you're up to, and when I do I'll-!"

Zim suddenly grabbed Dib by the throat, squeezing hard. He stared up at his nemesis with a cold expression, his face angry and vengeful.

"I am tired of this same daily routine," Zim said softly, pulling him close. "If it weren't for my respect for you as an adversary in battle, you'd have been killed a long time ago."

Dib stared at Zim, trying his best to pry the alien's hand off of his throat, shocked that he'd resort to this level of violence this soon.

Zim reached into his pocket. "I am not feeling like myself today, so I will tell you once more. Leave me be," he pulled out a knife, gripping the handle tight. "or I'll gouge your eyes out."

Dib struggled harder as Zim held the blade up to his face, pressing it to his cheekbone. The metal was warm and sharp, and Dib stilled immediately.

This wasn't like him. Dib felt afraid, for the first time in a while. Truly afraid.

"If you say one more word to me, I'll give you a demonstration on that child over there," Zim said quietly so only Dib could hear, nodding at Keef, who sat a few rows away behind them.

Keef met Zim's eyes and waved to him with a smile. Zim scowled and immediately looked away.

Zim released Dib and shoved him back, and Dib hit the seat behind him and fell onto it.

He looked at Zim with shocked eyes, panting and rubbing his throat. He gripped the bus seat, staring with wide eyes.

Zim slouched in his seat and put the weapon away in his pocket, once again looking out the window.

Everyone else didn't seem to notice, talking and laughing like usual.

Dib kept his eyes on Zim, now feeling, in his own opinion, uncharacteristically frightened of the alien. Zim seemed like he genuinely was in the mood to seriously hurt someone with his bare hands today, and Dib did not want to see what happened when Zim was pushed past his breaking point.

Dib thought about getting everyone else's attention to warn them of whatever was about to happen, but at that moment, Zim suddenly got up from his seat, his boots making heavy thunking sounds as he walked to the front of the bus. He didn't seem to be in any rush, either.

Once Zim reached the door where the driver sat, he opened it and slipped inside the cabin, shutting it behind him.

The door shut with a loud bang, and a few of the kids paused for a second at the sound, and then continued talking and speculating on what kind of field trip they would have this time around.

Dib tried to get up from his seat to follow Zim and document whatever he could find out, but as soon as he stood up, his path was blocked by two of his fellow classmates, Torque and Carl.

"Hey! Where do you think you're going, you little freak?" Torque sneered at Dib, shoving him back against the bus seat. "You shouldn't have came with us on this trip, nobody wants you here!"

Carl giggled, apparently pleased with the way things were going so far. "Yeah, we don't want you here!" He echoed. "Go back home and cry to your daddy!"

"Well, I'm here whether you like it or not!" Dib said defiantly, not breaking eye contact with Torque. "And one of these days you're going to have to just accept the fact that I'm- WOAH!"

Suddenly the bus lurched to a stop as though the driver had abruptly slammed on the brakes, throwing Dib and the rest of the kids off balance.

Dib crashed into Carl, who quickly shoved him violently to the ground. Torque fell into the seat next to him, but was otherwise fine.

"Hey! What was that?" Zita yelled out in confusion. "Did we just stop moving?!"

"Yeah, what's the big deal?" Melvin chimed in next, followed by the crowd of kids erupting into various questions all at once, and demanding answers.

Zim came out into the hallway a few seconds later, shutting the metal door behind him and walking back down the aisle towards Dib and the others, not saying a word to anyone.

The alien pushed Chunk aside when the kid bumped into him, and then kept walking.

"Hey look, it's Zim!" Torque smiled as he quickly blocked Zim's path now. "What's going on, little guy?"

Dib sighed, knowing where this was heading.

"Move aside, you inferior worm!" Zim demanded angrily. "I am busy and do not have the time for your pathetic games!"

"Well, too bad!" Torque said with a grin. "Now that we're not moving, we have all the time in the world! Right, Carl!?"

"You got it, Torque!" Carl agreed stupidly, nodding along to his friend's statement.

"Show him who's boss!"

"Move aside this instant, or I'll pull out your intestines and strangle you with them!" Zim threatened, his fists shaking at his sides.

Dib watched as Torque laughed in response and shoved Zim to the ground, the fake dog being once again projected on the bus's windows, though it was now frozen in place.

It looked eerily accurate to the real thing, so Dib had to give credit to Zim for that, he supposed.

"You are making a BIG mistake," Dib warned Torque, walking up behind him and trying to pull him away from Zim. "He's not messing around!"

The Irken glared up at Torque from the ground, his eyes filled with pure malice. Dib knew that look, and it meant trouble.

"Oh yeah, what are you gonna do about it, Dib?" Torque sneered, turning to confront the investigator. "You're even weirder than he is!"

Dib stared at Torque, not backing down. He wasn't going to give him or anyone else the satisfaction of letting them win.

Zim slowly got back to his feet. Carl grabbed the front of his uniform and threw him back towards the ground, his face hitting the edge of one of the bus seats.

The Irken turned around immediately and sprang back to his feet, one of his contact lenses now missing, exposing the red color of his real, alien eye.

Dib stared at it, ignoring Torque as Zim made eye contact with him.

Carl was also staring at Zim, mouth hanging open. "What in the fuck-?"

Zim slowly reached up and felt his face, fingers brushing over his exposed eye. Realizing the situation, he sighed. "Well.."

The Irken reached up and slowly started peeling off his other contact lense, then took off his wig.

Carl kept staring in shock, frozen to the spot and unable to move. "You're-!"

Nobody else seemed to have noticed the situation yet, too busy trying to figure out what the problem was with the bus's sudden screeching halt.

"Hey!" Torque lightly slapped Dib's face to get his attention. "Are you listening to me, you fucking waste of space?"

Dib turned back to Torque, his fists shook at his sides. "If insulting me makes you feel better about your shitty life, fine, go ahead and do that. I can take it."

Torque opened his mouth to say something, when something thin and metal and sharp suddenly protruded from the back of his throat, bursting from his mouth.

Blood spilled onto the floor of the bus as Dib stared in shock, frozen to the spot much like Carl was.

The metal appendage raked upwards, carving straight through the rest of Torque's head and splitting it in half. Bits of brain matter sprayed upwards and hit the ceiling, sticking there like the potatoes from the Skool cafeteria. The blood flowed out more forcefully now, trickling steadily. Some of it had sprayed Dib's shirt and face.

Torque's body stood for a few seconds, then collapsed to the floor.

Zim stood there, two of his PAK legs out, and his uniform was speckled with the blood of the human he'd just mercilessly slain.

His face was pure hatred and determination, fed up with several years worth of insults and bodily injuries.

Everyone else started screaming.

Then it was chaos.

Zim drew some kind of weapon, resembling a small blaster from his waistband, and fired it at Zita, her head whipping backwards as the bolt of plasma burned a hole in her face. She collapsed to the ground as blood immediately started spilling out of her body.

Carl was next. Zim drew the knife that he'd threatened Dib with earlier and twisted his body towards him, quickly and efficiently cutting his throat open.

Cal started choking on his blood and slowly fell to the floor as Zim moved on.

Then the Letter M was stabbed through the abdomen by a PAK leg, the metal appendage running him through and bursting out of his back.

Finally remembering how his legs worked, all Dib could do was run to the back of the bus and cower in fear under the farthest bus seat, curling himself into a tight little ball.

The screams of his dying classmates would forever be trapped in his mind, haunting him until the final days of his life.

He heard someone begging, and Dib peeked out briefly and saw Flan being choked by Zim, a PAK leg posed to strike.

"Please!" Flan spoke raspily, "We were only joking, don't you understand? We just-!"

The PAK leg was thrust through Flan's face mid-sentence, piercing through the back of his skull, and his body went limp. Zim let him go and he fell to the floor.

Dib curled up tighter under the seat, practically cradling the wall of the bus. He'd never been more afraid than he was right now, trapped on a bus with a mass murdering alien who had finally been pushed past his breaking point.

He started to cry silently, muffling his sobs in his shirt. He was terrified, unable to help the rest of his classmates as they faced their doom.

He covered his ears to silence the loud screams of the victims, tightly shutting his eyes and desperately wishing to be back home with Gaz and his dad, eating breakfast and talking about nothing in particular.

He should have appreciated life more, he should have spent more time doing things he wanted to do instead of constantly hunting an alien who seemingly didn't have what it took to truly conquer the planet.

He wasted his life, trying to expose Zim to people who would never listen.

The screams died down as more people were killed, and Dib mentally berated himself for not going out there and helping his classmates.

But why would you? His inner voice asked, they've been nothing but cruel to you, they deserve this.

Someone fell to the floor across from him, (Chunk his name was) and Dib recognized him as one of his most vicious tormentors.

Chunk locked eyes with him, reaching out a shaking, bloodied hand towards him, mouth moving in an ill attempt to perhaps form some kind of pleading desire for assistance.

Dib stayed silent, still curled up on the filthy floor of the bus, trying to form some kind of plan for escape or to at least fight back lest it be his turn to suffer the same fate as his fellow Skoolchildren.

Heavy footsteps approached his position, Zim's shadow looming on the wall as the alien stood over Chunk's dying body.

Dib started scanning the rows of seats, forming a plan to move.

Chunk tried to get to his feet, but Zim put his boot on his back and pushed him back to the floor.

Zim bent down and rummaged through Chunk's pockets, searching for something. A trophy, maybe? Dib wasn't sure.

Then Zim froze, his hand in one of the boy's pants pockets, and pulled out what looked to Dib like a switchblade, the dark red handle gleaming in the light.

The alien examined it for a moment, turning it over in his hands as he figured out how to open it.

He pressed a button on the side of the handle with his thumb, and the blade sprang up, thick and sharp and deadly.

Zim stood up and grabbed Chunk by the hair, yanking his head back. He slowly raised his arm as Chunk looked up at him in fear, desperately attempting to pry the alien's hand off of him. "Wait, wait WAI-!"

With what sounded like a growl, Zim thrust the blade into the side of Chunk's throat, shoving it in all the way to the handle.

He yanked it out, and Dib covered his mouth as tears started forming in his eyes.

Chunk immediately started spewing blood, choking as his face contorted into shock and pain. His blood painted the seats beside him, staining them red.

Without a word, Zim let him go as well and walked in the other direction towards the front of the bus, wiping the bloodied knife on his uniform, which was already stained and ruined with the blood of his many victims.

Dib thought about reaching out a hand to provide Chunk with solace in his last moments, but before he finished fully processing the thought, Chunk became still and silent, and his blood stopped all activity.

Chunk died staring at him.

Dib peeked his head out again for a second, seeing that Zim was too preoccupied with stabbing Gretchen in the eye to notice him.

Gretchen's head snapped back as her bloodcurdling screams and wails of agony chilled Dib to the bone.

Zim grasped the handle of the blade and twisted it, making Gretchen scream louder and more forcefully.

He violently yanked the knife out of her eye, and a trail of blood flew back and hit one of the seats, dripping down the leather material.

Gretchen clawed at her face while still wailing, smearing her blood all over the rest of her face.

She was stabbed in her other eye, her screams stopping immediately as her body stopped moving. She fell to the ground as Zim pulled out the knife and wiped it on his pants.

Dib slowly started crawling on his belly towards the nearest body, hoping to find something that he could use to defend himself against Zim.

A loud banging noise made him nearly jump out of his skin, and something heavy hit one of the seats near him. Another person, he knew, was being attacked.

Through the gaps in the seats, he saw Zim jump on Jessica's back and stab her twice in quick succession in the front of the throat, the blade poking through the back of her neck.

She slowly collapsed to the ground, spewing blood much like Chunk had done a few minutes before. Zim must have gotten lucky and hit some kind of artery.

Dib kept moving, sliding across the floor as quietly as he could to avoid detection. He scanned the area, a slowly spreading puddle of blood from a nearby body making him stop for a few seconds.

A severed head rolled towards him, the eyes open and very dead.

Dib put his hand to his mouth, staring at the head in shock. Blood still spurted out of the stump of the neck, trailing behind it as it rolled around on the bus floor. It was stopped by another body with a missing arm, amputated cleanly and efficiently.

Dib felt sick being around all of this carnage, and the smell of blood was thick in the air, and he felt dizzy and breathless, the fear overtaking his ability to think coherently.

Barely holding down the overwhelming urge to vomit, he reached out an arm towards another body and grabbed a pant leg, slowly dragging it towards himself. He checked the pockets but didn't find anything useful, only gum wrappers and a cell phone that didn't have a signal.

Of course there was no signal, he chided himself. They were in space, with nothing around them except millions of stars and no one to save them from their fate.

Zim, meanwhile, had just gotten hold of the last victim, Penny, his hand wrapped tightly around her throat.

Dib started moving a little faster, maybe he could distract Zim somehow and save the latest victim, maybe if he could just buy them a little more time, they could get help somehow.

Fuck this, he thought with a sigh, sliding out from underneath the seats. He wasn't going to spend what little time remained of his life hiding like a coward, he was going to go out fighting his nemesis just like always, even if this time Zim was an actual, legitimate threat to his life.

"Zim!" He yelled out, trying not to look at the dead bodies scattered around the bus. He felt something warm soak into the shoe on his left foot and wet through to his sock, but he didn't look down to see what it was. He knew already by now.

Zim froze, turning his head around and locking eyes with Dib. His arm was poised to strike, in line with Penny's mouth.

They stood there for a few seconds, staring at each other. Most of Zim's uniform was covered in blood, and his face was speckled with it as well, and the blade of the knife he was holding was also dripping with blood.

He looked like something out of a slasher movie.

Eerily silent, the alien dropped the small switchblade (the weapon clanging against the floor and bouncing briefly and stopping by Zim's feet) and pulled out his blaster, which had been tucked snugly into his waistband, and turned it on its side, briefly checking the amount of ammo he had left in the cartridge.

"Zim, please stop," Dib begged. Though he knew his efforts were probably useless, he knew that he would regret it for the rest of his life if he didn't at least try to talk sense into the Irken. If he didn't try to save at least one life from his inextinguishable wrath. "Please let them go, she's just a kid. She never did anything to you."

Zim tilted his head, his eyes glazed over with…something. Was he high on something? Maybe some kind of alien drug?

Slowly his face became an expression of hate, his lips pulled back and his antenna pressed back against his head. An obvious sign of defiance.

Quick as lightning, Zim pressed the barrel of his blaster against the underside of Penny's chin and fired a single round.

Her head whipped back from the force of the blast, part of her skull vaporizing in a spray of bloody mist as the walls and ceiling were coated with the fluids. Zim dropped her, staring at the body as the blood quickly started pooling around her.

"No!" Dib cried uselessly, running towards the Irken instinctively.

Zim aimed the blaster at him and fired, the round missing Dib by inches, the red laser of pure energy hitting the back wall of the bus and leaving a black scorch mark on the surface of the metal.

Three more rounds were fired, and Dib somehow dodged the first and second one, but the last round hit him in the side, tearing through his clothes and skin.

He howled with pain, clutching his side as his body briefly went numb. He felt the warm wetness of fresh blood begin to soak through his shirt.

Zim walked up to him and grabbed his throat, punching him twice in the diaphragm with lightning speed.

Dib collapsed to the floor gasping for air, but Zim grabbed him by the collar of his shirt and forcefully lifted him to his feet, backing him up against the wall by the front door and slamming his body against it.

Zim choked Dib with a force that the human didn't even know he was capable of, strangling him as he pressed the barrel of the blaster hard against Dib's forehead, the weapon stinging hot from recent use.

He squeezed his eyes shut. This was it, this was the end. All the years of monster hunting and paranormal investigations. All that time wasted trying to prove that Zim wasn't who he claimed to be, forgotten in the blink of an eye.

The blaster made a faint clicking noise.

Another.

Dib slowly opened his eyes.

Zim pulled the gun away, a look of confusion on his face, and checked the ammunition. A red light was flashing on the side, indicating that the cartridge was now empty.

Zim scowled and flung the blaster to the ground, delivering a hard punch in Dib's diaphragm.

Dib instinctively tried to double over, but Zim grabbed his head and slammed it back against the wall, forcing him to stay upright as the human struggled to breathe.

He struggled in fear as one of Zim's PAK legs emerged, slowly moving towards Dib's eye.

Zim's face was etched with pure hate, his lips twitching as he stopped a hair's brush away from Dib's eye.

He was waiting for Dib to do something, he knew. He wanted an excuse to kill him.

Not that Zim needed one. He had just mercilessly slaughtered a busful of innocent humans, after all.

"Why?" Dib gasped, clawing at Zim's hand crushing his trachea. His side burned, and he could hear his blood dripping onto the floor. He was in agony, but he wouldn't let Zim see his weakness. "Why did you…do this?"

Then Zim finally spoke, his voice low and threatening: "You know why." He pressed harder on Dib's throat. "I'm sick of observing. I'm giving myself a new objective. I'm killing as many of you pathetic humans as I can, and you won't stop me this time."

Dib began to see stars as his vision started to fade.