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// Chapter Nine: Into the Portal and Through the Universes We Go! 
// Story: Ponies Playing Doom 
// by obake 
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Rarity pondered the plans Discord had laid out for her as she packed the last of the supplies into the bag with her cutie mark symbol on it. In front of her was the television screen that the demons had entered through. By now the convention was a ghost town, concession stands and buildings empty of all but evidence that they had recently been inhabitated. 
The conversation with Discord reeled in her mind. 
"You will infiltrate the world of Doom." he said. 
"Are you sure it will work?" 
Discord grinned unpleasantly. "Why, don't you trust that I, a friend, knows what to do?" 
"Well, no."  
The answer was candid enough that Discord simply burst out into chuckles. "Ah, I can't stay mad at you. Even when I know you don't believe a thing I say."
The atmosphere of the room grew more tense as time seemed to melt into more and more oblivion. 
"Please," Rarity begged, "just tell me where to go." 
"Alright," said Discord, "The demons appeared through a giant television screen at the convention."
"Yes, and?"
Discord gave an annoyed glare. "And that television screen is the means by which their world came into ours. It is also the means into which you will travel in to their world."
"Their world?"
Discord used magic to suddenly appear as a Cyberdemon, causing Rarity to jump back. Then, the guise melted into an obviously shoddy, ridiculous costume of a Cyberdemon. Discord lifted the latex mask from off of his face and nearly sang "You will be in the Doom universe for real! Only this time, if you die, it's permanent."
Sweat ran down Rarity's face. "But can't I-"
"Uh-uh-uh" interrupted Discord, waving a finger. "You're the one whose trained to get the job done. All Equestria asks is that you do it well, without failing." An ever widening smile came over Discord's face before he erupted into erroneous laughter. But when he saw Rarity's expression of panic, he toned down. Stifling a smirk, he added "But don't worry about it, you will succeed."
Rarity's voice was quiet, mouse-like. "How do you know?"
"Because the Princesses trust in you, that's why." 
Rarity hoped that was the reason she was going through with these plans, the reason that she slowly stuck one hoof through the TV screen, and then another, and finally walked full force into the depths of an alien world. Her only hopes were to vanquish the evils that had infested her home. Otherwise, she was doomed. 
Little did she realize, that stowing close by, a certain filly followed into the same dangerous portal, right behind her. 
But, it wasn't Scootaloo.

Rarity's surroundings warped and stretched into thin veils, swirling back and forth like curtains in a breeze. All she could see for a moment was total darkness. Then, a faint hint of light. It was impossible to tell whether it was streaming in from the far end of a tunnel, or if the source was simply a tiny, iridescent orb in front of her. 
Whatever it was, Rarity inched towards the light. It was apparent now that it was indeed from a far off source, but what was making it? Surely it could not be the sun, or anything pleasant, right? 
Rarity's mind wandered to Celestia, and how the princess controlled the sun. If anything, Rarity wanted Celestia along her side, seeing as somepony with such amazing magic might be able to add some level of comfort to where she was about to venture. 
But it was not Celestia that hitched along. Rarity heard steps behind her, freezing in place at the thought of being attacked. Instead, she saw her little sister. 
"Sweetie Belle!?" 
Her filly sister smiled sheepishly back. "The Princess wanted me to go with you." said Sweetie Belle, "so she teleported me here."
Rarity scoffed, unable to form a reply. First she was angry, then confused. Princess Celestia? But why would she send Sweetie-
A loud clank from afar broke the silence. Their surroundings had become more clear; they were in some sort of industrial tunnel,  almost like a mineshaft but more advanced. Aluminum signs plastered walls where exposed pipelines and wires stretched from ceiling to floor in curious, maze-like fashions. The stench of chemicals was strong. 
"Where are we?" asked Rarity, momentarily forgetting the discomfort of her sister's presence. 
Sweetie Belle shivered from the cold, moist air. "I d-don't know," she replied, "but I bet we'll not want to stay long."
Seeing as there was no means of getting Sweetie Belle back home, Rarity let her tag along, but only by having her little sister cling tightly onto her back. 
The tunnels seemed interconnected at random, uneven angles, like a scribble. Sweetie Belle felt bad for lying to Rarity about how she got there. Princess Celestia did not teleport her, Discord's did. 
All Rarity could think about was the fact that minutes ago, she was going towards a faint light in the distance, but during the confusion of seeing her sister, the light vanished.
She shook her head and thought that the light's whereabouts was of least importance at the time. "Sweetie Belle, I really don't understand why Celestia would send a filly on a mission like this."
"H-She told me it was what needed to be." said Sweetie Belle, "That, without some help, you wouldn't be able to survive the last boss you are looking for."
"Hogwash! That's like something Discord would say." Rarity snapped.
Sweetie Belle blushed and expected to receive a scolding. But Rarity continued on "The fact that the Princess would say that means Discord's influence must be rubbing off on her. That disgusting creature. Even when he "helps" somepony, it is only to laugh at them behind their back!"
Sweetie Belle tilted her head. 
"Sorry about my ramblings," said Rarity, "I'm just so caught up in the emotions of the moment, being in this dark, treacherous labyrinth. Not knowing where to go..." 
Sweetie Belle tried to interrupt, but Rarity kept speaking, "This place is simply a disaster. Imagine trying to tidy it up to even a decent standard. It would still be more than a century's wor-"
"Rarity!" Sweetie Belle shouted, pointing in front of her.
"What-" Rarity stopped, her mouth agape. Sweat drew down her forehead. Her tongue dried. "Are, are you-"
A figure, covered head to toe in familiar green and grey, space-age military attire, guns protruding from the backpack on his back, and double-barreled shotgun in his hands, stared puzzled. 
"You're the aliens my enemy said were coming to stop him? I expected something...not so colorful."
Without hesitation, Sweetie Belle chimed "We can give you a pair of sunglasses if our colors hurt your eyes!"
"Really!" Rarity yelled back.
The marine held his hand up. "No need to yell, I'm fine with that suggestion. I'm just glad help has finally arrived. Ever since...that day...things have been so much worse."
Sweetie Belle was going to ask what that day was, but Rarity spoke first in shock "Are you saying, you want our help?"
"Exactly," said the marine, "you two may be the only shot this universe has at defeating Hell. The question is, are you ready?"
A moment of complete silence. Then Sweetie Belle gave a military salute. "Yes, Mr. Marine. We are ready to save the world!"
Rarity was not as confident.
The three walked on, visiting areas known to avid Doom fans; UAC bases, hellish dungeons and distant castles. All of it seemed to go by in a blur, yet there were no enemies, as if the two ponies and the Marine were the only beings in existence. But that was to change quickly.
Sweetie Belle rolled her eyes. "Uggh." she murmured, "Another techbase? We've been through what, five of these already? I was under the impression there would be lots of action and suspense, not...endless wandering."
The Marine laughed. "Yeah, I guess with most of Hell's army invading your universe, its left ours a little bare."
"That's not smart." said Rarity, "wouldn't Hell keep itself guarded with a sufficient army. What is it's strategy, hope no takes over their bases when they leave them abandoned?"
"I don't know," said the Marine, "but you can bet that they have something in store for us. Maybe they're letting us get to them first, then they'll spring forth their devious plans."
"I hope so," muttered Sweetie Belle.
"Come now, Sweetie," Rarity scolded, "are you really wishing our journey to be treachorous?"
"I don't even know what that means," said Sweetie, "but it sounds better than being bored."
"Hold it," said the Marine. As the sisters arguments went on, they little noticed the areas they were traversing. They were now inside a large, square room surrounded in nukage, with only a small bridge going down the radius, of which they were on.
"It's hot in here." said Sweetie Belle. "Can we get out of here?"
The Marine pondered. There was a lone radiation suit, lots of open nuclear pools,  and an inaccessible door across the other side of the room. "The only way out," he said, "is through that door on the other side, but one of us will have to swim around in the pits until they find the switch to raise the other half of the bridge."  
"Will that 'person' be you?" asked Rarity. The radiation suit in question was clearly not shaped to fit a pony. 
The Marine pondered. "No," he said, "I can't be the one who wears it." 
"Oh, for heaven's sake, why not?" asked Rarity.
"Because that." The Marine pointed towards a large number of Lost Souls rising from one end of the toxic pool."
"Aw shucks." said the Marine, "You'll have to don the suit, Sweetie Belle. Swim through the nukage and find the lever that raises the rest of the bridge."
"Me?" Sweetie Belle gulped. Not wanting to look childish in front of her big sister, though, Sweetie Belle accepted. 
Rarity called in protest, but Sweetie Belle quickly donned the over-sized suit and dived into the sludge, while screaming skulls launched from various directions. The sound of the Marine's chaingun was so much louder in life than it was in the game. Rarity could barely hear herself speak as she ducked to dodge another Lost Soul. Luckily for her, another Lost Soul was launching at Rarity from the exact opposite direction. The two demonic forces smashed face first into each other, bursting into a glorious spark of fire and blood. Rarity was unharmed. 
"Let me have one of your weapons." she said.
"As you wish." 
The Marine threw over a Plasma Rifle. Rarity gave a sadistic grin. She stood on her two hind legs and spammed the trigger all over the place. Plasma bullets spread all across the oncoming hordes of Lost Souls, wounding many, and even killing a few.

Meanwhile, Sweetie Belle was swimming in a tunnel connected to a wall underneath the pool. It seemed to be some sort of ventilation shaft that had become flooded. Fans did their darnedest to spin around in the sludgy depths, while overhead lights flickered. Finally, she reached another room, where she swam up and head above the nukage. A set of stairs led out of the nukage and to a door. Somewhere safe, at last! she thought. Sweetie Belle knew the effects of the suit were almost out. Fate had it so that as soon as her last hoof had left the slimy toxic waste, the suits effects were complete. She sighed with relief, pushing back the thought of how she was going to get back. 
All the while Rarity pumped the last Lost Soul full of plasma lead. Her entire frame was covered in dirt and sweat, which in any other circumstance would make her uncomfortable. But for where she was, it seemed appropriate. 
"Good work." said the Marine. 
"Thanks."
"I wonder how Sweetie Belle's doing."
Rarity gritted her teeth. She had been so caught up in fighting off the invading skulls that she had forgotten her sister. "She must be fine, right?" She looked at the Marine.
He shrugged back. "Probably, as long as-" He saw Rarity's disdain and promptly quit talking.
Sweetie Belle, on the other hoof, had her own troubles. Her tiny frame could not lift the behemoth door even an inch. She wished Scootaloo and Applebloom could have been there to help, but of course, how would they get here with just one suit?
She eventually cursed and gave the door a good kick with a hind leg. This gave her an an idea. She knocked hard on it multiple times. She knew that in the Doom universe, it was likely somepony or something would hear her and go to investigate, opening the path for her. The trick was making sure she wasn't caught by whoever opened it. Sure enough, something heard and was getting closer. 
A single pair of footfalls echoed from the other side. The door began lifting at a snails pace. Sweetie Belle prepped herself to run. 
She imagined going through this process in heroic fashion, making a fool of a buffoonish bad guy while hitting a switch, running in more circles, and last of all escaping with an extra radiation suit. Instinct told her that she was in for something less favorable. 
She gave an adorable whimper at what was before her. A single Pinky Demon on foot, and what seemed to be thousands of grinning Cacodemons cackling back at her. 
Sweetie Belle would have said an expletive, but this is a family story. Instead, she merely screamed and ran forwards. The monsters, not expecting the filly to run towards them, jumped back in surprise. A few of the Cacodemons shot lightning balls, but they missed. Sweetie Belle was running through corridors, mazes, hallways, with no sense of direction or idea of where to go. Every door she came across, she kicked with her back legs, causing it to open. Monsters busy inside the other room were suddenly distracted by the hyperventilating filly. Sweetie Belle almost seemed doomed. Monsters of every type from the game were surrounding her in the maze of hallways, set up like...a hospital? A mancubus, more rotund and terrifying in person than Sweetie Belle would have imagined in her nightmares, raised its arms to shoot. Sweetie Belle braced for impact. 
A deep groan of pain, but it wasn't from her. She saw that a Cacodemon's shot hit the Mancubus in the back. The two monsters began charging towards each other in a brawl. The Mancubi's shots hit both the Cacodemon and multiple monsters around it. Monsters from all over the place started hitting each other inadvertently, allowing Sweetie Belle to dive under them and keep running for her life. 
A Former Human holding a cup of coffee tried tripping Sweetie Belle with his leg, not realizing how much she weighed. The two bowled over like pins, the cup of coffee flying backwards and out of the zombies hand, scorching the face of a Chaingunner. Sweetie Belle quickly got back on her feet and ran like the wind, while the temporarily blinded Chaingunner shot wildly at the walls, breaking window glass and knocking over a canister full of cigarette ashes. 
Sweetie found herself at a room called "Maintenance". Without hesitation she smacked into the door, and ran inside. To her astonishment, in the room was lamp illuminating a desk, and on top of that desk: A blue keycard! Sweetie knew she was lucky. She must get that card!
She leaped onto the table, only to find that also on the table was a jacket, underneath of which she had awoken a sleeping Archvile. 
Time goes by fast when you are about to die. That is all Sweetie could think about as she swooped under the desk, the keycard in her mouth. She realized foolishly that the desk had drawers or anything to hide under. The Archvile looked directly at her from under the table. Spinning its song of fire, Sweetie Belle fumbled her way forwards, tripping over a cord. The spell was about to be complete when it was interrupted by shattering of glass over the Archvile's head. The cord she had tripped on had caused the lamp to tip over. Sweetie Belle leapt out of the room, hitting her head on the top of the table as fire and sparks illuminated (caused by the lamp breaking, not the Archvile) spread across the top of the table, the walls, even the carpet. 
Sweetie Belle did not realize until she was halfway down the next hall that her tail was on fire. "Mmmreeg!" she screamed, still clutching the key card tightly in her teeth. She did the best to bat the fire away, frantically stumbling to and fro as she inexplicably set more things aflame. She even knocked over a pedestal with a statue atop it. The marble figure seemed to cling for dear life in mid air before smashing down a Demon that had been chasing Sweetie Belle from the beginning. 

Meanwhile, Rarity and the Marine waited. Minutes went by in silence. The Marine looked at his watch. Rarity sighed uncomfortably. The two had not spoken another word, yet silently, they both had thoughts running through their mind: Do we go for Sweetie Belle, or wait?

Sweetie managed to find a bucket. She batted away the mop and plunged rear-first into the filthy water. The fire died, and Sweetie breathed a sigh of relief. As she realized how disgusting the water was, she dove out, knocking the bucket onto its side and spilling its contents. The stuff bore an unbelievable smell of moldy food mixed with detergent. Clods of dirt and leaves floated along the surface like ant-sized boats. Sweetie Belle's ran far away from the bucket.
When she had a chance to pause, she looked at her surroundings. The office-like corridors and meeting rooms were now furnished with gray bricks and long tables. This made Sweetie wonder whether her ventures  gradually led to this castle setting, and that she was too busy with other things to notice, or if it changed all of a sudden. It was not too-far fetched a thought, at this point. 
In the corner of the long room was a door illuminated on both sides by blue lights. Blood splashed on the door trickled down into a glaring, demonic face. "I-I'm not afraid" thought Sweetie Belle. She had the blue key card, so she would be able to venture into the locked blue door before her, afterall. That was what she was afraid of.