"You're probably wondering why we've summoned you on such short notice," Celestia's voice said to the six as they approached the throne in the main hall.
"What's the threat this time?" Rainbow asked excitably from above the group. "Changelings again? Discord?"
"We don't know," Luna said as she stepped in. "Not exactly, anyway."
"About four hours ago, Luna detected a new presence near the moon, something living," Celestia said as she approached the group. "We are dealing with a new unknown life form. Perhaps they are friendly, perhaps they are not. Whatever the situation, we must be prepared."
"Has the military–" Twilight started.
"Yes. They are on full alert, and the royal couriers have been scrambled to deliver the news to all other countries, regardless of the current relations," the solar diarch interrupted.
"So if the military is on call, why are we here?" Applejack asked. "We aren't fighters. We're just a group of friends."
Celestia turned to her, "We've brought you here because the Elements of Harmony are the greatest defense Equestria has. In the event of catastrophe, they can restore thousands of years of chaos and destruction."
"So what's the plan for us?" the farmer inquired further.
"We need you to stay in the castle with the Elements," Luna answered. Her expression was grim, as though she knew this encounter would not end well. Applejack, being far more observant than others gave her credit for, had a sneaking suspicion that it was not simple anxiety or premonition. The princess had evidence, and understood the severity of that evidence. And though it could only truly be a hypothesis, the dark alicorn had reason to believe that hypothesis to be the truth of the matter. "There is a bunker beneath here, and it is stocked with enough food and fresh water to last a month."
"Why not seal us in the vault with the Elements?" Rarity asked. "Or possibly take the Elements down to the bunker with us if we must?"
"The vault is airtight. You would suffocate inside," Celestia answered grimly. "The bunker will hold. It is enchanted to withstand even the force of a caldera blast. As for taking the Elements with you, I don't believe that would be the wisest decision. Any Guard can open the bunker's door, and if one turns sides or is forced to open the door, the Elements will be in danger as well as you."
"Anti? Counter? Could you please escort the Element Bearers to the bunker? Time is running short," Luna called. "Sister, they've just passed the moon. They're coming down on Equestria."
"Where do you think they will land?"
Luna's face became even more serious than it already was. "Our front door."
Two thestrals stepped into the throne room, bowing at the entrance. They wore more armor than the Guards normally wore. This was likely due to the alert from the princesses, as war armor and standard armor were made with different metals and enchanted with different spells at different times in the forging process. The two bat ponies saluted Luna, then gestured for the six to follow them.
They were led down hallways that they had seen before, then some they had not. They soon reached a door that never existed, an enchantment making it look like it was just a wall. Through said doors, was a staircase that led down into darkness only thestrals and Luna could see in unaided. Twilight used a simple light spell to illuminate the halls for the six, revealing that the walls were not even masonry. The walls and ceiling were simply dug out of the ground like a mineshaft, the only hint that ponies had been here being the stairs, which were made of uniformly cut bricks. Every so often a gem would be sticking out of the walls, and a set of doors would be set into the stone. Some were false doors, made to look functional, but opening only to a wall.
Soon they approached a door that looked like every other: dark wood with brass fittings and handles. The two guards pulled open the doors and bowed to the six, the tiny flaps on their necks twitching. Not a moment after, the crystal lamps in the room lit up in a soft but bright yellow light. The room, unlike the hall, was masoned properly, a light-colored stone used to support the walls. The group stepped in, noting that it looked almost like a normal home setup. Set into the ceiling was a metal vent, where air seemed to be flowing in from. Set into the floor was a similar vent that seemed to be pulling air out. Off to the sides were a few doors that seemed to lead to individual bedrooms, as well as other rooms necessary for living quarters. Set into one wall was a sort of flameless hearth, enchanted crystals providing both heat and light. Next to that was a kitchen, which was probably stocked with enough food and water to last a very significant amount of time.
"Don't answer for anyone. Only the princesses and us guards can open the door from the outside. If it knocks, it's not friendly," one of the Guards said curtly. Without waiting for thanks, the two bat ponies turned and left the bunker, the doors closing behind them, leaving the Element Bearers sealed inside.
------
"Why must these things have such thick armor?" Shirska cursed in his native tongue, firing another pair of hand cannon rounds into a Legionary's bright green helmet, though it didn't do much aside from denting it. The Legionary roared savagely beneath its helmet and returned the transgression with a pair of rounds from its slug rifle, which Shirska was more than agile enough to evade. The ponies were still unconscious behind the block of stone upon which Shirska was fighting off the Cabal. "Die you clumsy two-armed whelps!"
It took four pairs of hand cannon fire to puncture the Legionary's helmet, leading to the thing's airtight seal being broken and causing explosive decompression. The helmet shot off the Cabal soldier's head and flew off into the air and disappearing into the sky. As the soldier fell to the ground, another took its place, making Shirska growl in frustration. "Too many munitions spent for too few deaths. Hardly worth the fight."
Behind him, Applejack whimpered and shuffled. Though the Fallen didn't look back to the ponies to check who was moving, he knew it was Applejack. He was very good with voices. While he was unaware of the magic at play on his new and unlikely friends, he vowed to defend them until his dying breath. He calmly reloaded his hand cannons, noting that he was running low on munitions for them, and brought them to bear on one of the seven remaining Legionaries. As he was about to pull the triggers, he saw a Psion out of the corner of his eye, and turned one of the high-powered pistols on it. He liked the smaller, sneakier Cabal soldiers. They were easier for him to deal with, though they were slightly harder to keep track of as a result. But all the same, he hated all of them simply because they had decided to attack him and his friends here.
"If it comes down to it, I will borrow their weapons," Shirska said. "I hope it does not."
------
Down in the bunker, time passed slowly. The six tried to stay calm, but with no information, speculation quickly began to toy with the minds of the ponies. Twilight paced in circles in the main room, her hooves clopping in steady rhythm on the hard stone floor. Rainbow preened at her wings, trying desperately to distract herself, but knowing full-well that thoughts of the worst would come eventually. Fluttershy sat on the sofa in the front room, watching Twilight pace and shivering, fear already gripping her with its icy claws. Rarity stood in the kitchen, going over inventory for the thirteenth time. And Applejack was sitting in a corner with her hat tipped over her eyes. She was arguably the most afraid out of all of them. She knew she was strong, but there were limits to that, as she'd learned last applebucking season. What would happen when they left the bunker? Would it be safe? If it wasn't, Twilight and Rarity were the only ones with magic if they needed any offensive power beyond their hooves. Her strength meant nothing if that was the case. Rainbow's speed meant nothing if they brought her down. As she understood the situation, she was effectively useless until the Elements were in play.
A whimper from Fluttershy broke the near silence, and was answered by Twilight sitting down next to her, laying her head across the pegasus' shoulders. Applejack looked up for a moment, seeing Fluttershy drape a wing over the unicorn, still shivering. The two were complementary to each other, the farm pony thought. They brought out the best in each other. Twilight managed to coax the timid pegasus into doing things she would normally be too frightened to do, and she was able to calm Twilight down in the event of a panic attack. They didn't have harsh contrasts like herself and Rarity did. Those two simply accentuated the best parts of themselves and helped each other work past their flaws. If they got past their awkwardness and their denial of what she sensed to be obvious attraction, Applejack thought they could be the couple that ponies envied.
A tremor shook the bunker, followed by more. They couldn't hear voices, but they knew that the rumbling in the floor was not natural. A full-grown dragon could make such quakes from walking, but Twilight doubted this was what was going on on the surface. For a few moments, all was quiet once more. Twilight tried to listen with magic to what was going on outside, but the enchantments on the bunker prevented her from doing so. Frustrated, she tried another iteration of the spell, hoping that she could find one that could pass through the enchantments. Again, and again, and again she tried, quickly exhausting every version of the listening spell she knew, until finally success found her. She could hear everything through Princess Celestia's ears.
"I've got ears," Twilight said to the group. "I'll see if I can't get eyes."
"What's going on now?" Rarity asked, poking her head out from the kitchen.
"Celestia's trying to break the language barrier," Twilight answered, casting a new spell that was similar to the one she'd just used. "She's trying enchantments."
"Let us know when she suc–"
"She's got it," Twilight reported. "She's asking their purpose."
The others sat still as statues listening intently to Twilight's reporting. It was all they had to judge on, and they wanted to know as much about the situation outside before they did anything.
Up above, Celestia remained outwardly calm, though she sensed something very wrong with the entirety of the situation. There were sentient aliens in a spacecraft on the castle grounds, holding what she could only assume to be weapons, in armor-plated suits. They spoke a rough and guttural language, and walked in clumsy stomps. They acted like an organized and highly skilled military force, which made every gesture that much more important to be wary of. Her guards, at best, could take down a few of them with magic if they weren't killed instantly by the aliens' weaponry. She herself could hold her own in a fight, and Luna could perhaps repel them, as she tended to be far more of a fighter than herself.
"I Aventus Da'axus. We explorers," one said. The owner of the jagged voice stepped forwards, establishing himself as the leader of the group. His helmet had a bright red plume on the top that swept from the forehead to the back of its head. On his pauldrons were similarly decorated with colorful plumes, made with the hair of some creature and dyed. From the back of his armor stuck out two flat sheets of metal that looked almost like wings. Whether these were functional or merely aesthetic, the princess could not guess.
"Welcome to Equis. I am Princess Celestia, and this is my sister, Princess Luna," she said, introducing herself and her sister to the bulky aliens.
------
Shirska had run out of ammo for his hand cannons, and was now relying on his auto rifle, which had far less power than he liked, but was still a versatile enough tool of warfare for him to justify using. To his dismay, the weapon was not nearly powerful enough to reasonably handle the Cabal. The small battalion of heavily armored aliens had become progressively more aggressive, and now there were some with more advanced weapons systems. With the heightened difficulty of both killing and evading the enemy, Shirska was beginning to grow tired, and more of his ether supply was being consumed.
These factors compiled enough for Shirska to take a hit. A slug rifle shot from a Phalanx hit him in his left leg, knocking him down off the block. Groaning in pain, he picked himself up and switched to his rocket launcher, which he only had another two rockets for. He didn't want to have to use it, but with too many of the Cabal around with such thick armor, he had no real choice but to use the overkill weapon. As soon as he aimed the heavy weapon, he fired and then ducked behind the stone again to avoid getting shot again. The rocket sailed past the Phalanx and exploded just a meter behind it, sending the poor Cabal flying and losing its grip on its shield. When it slammed into the rock, it did so head first into the corner of the block, puncturing its helmet and depressurizing the suit. Knowing he'd need to quickly fire the heavy weapon again, he reloaded it before switching back to his auto rifle. When he poked his head back up, he counted his remaining enemies.
"Three of them, eh?" he grunted as he began feeling the pain in his leg from where he'd been hit. "I have plan."
------
Inside the palace, the princesses had spoken to the strangers about various topics, such as the political and military workings of their respective worlds. As it turned out, they were a military force sent by their home world to explore space, as Aventus had reported. When asked why they sent a full battalion of military infantry, the strangers' leader could only reply that he was not aware of why. He offered his own conjecture that it was for organizational purposes; the military was trained in battalions, and reached incredible levels of friendship and camaraderie with others in their battalion. It would make sense to keep the groups together for such reasons, as they found that units that worked in harmony with each other often survived battles that were stacked against them from the start.
As Twilight and the other Element Bearers waited in the bunker below, with Twilight reporting the action above much like a sports commentator, they felt their anxieties grow. As much as Aventus was acting friendly, all of them had a sneaking suspicion that he was not simply an adventurer sent from his home. Applejack eventually voiced her concern that the stranger was indeed lying, and that she could hear too much ease in his voice when speaking of his home, as though he had a script or had practiced what to say. In her experience, she had only found such a trait in malevolent liars, lawyers, and businessponies.
When the first shot was fired, Twilight screamed, fearing that her mentor had been the first victim. The others, confused and afraid, panicked, rushing to calm Twilight as she broke down into a crying mess. Fluttershy was arguably the most panicked out of all of them; her closest friend suddenly collapsing in unfathomable anguish making her extremely sensitive sense of empathy emulate what the unicorn was feeling.
When she finally was able to get Twilight calm enough to talk, Fluttershy and the others looked to her once more as their leader. Twilight had always known what to do and how to do it, and had earned the loyalty of her friends through trials by fire. Nightmare Moon was her debut as the leader of the Element Bearers, and ever since then, they had trusted her quick wit and careful judgement.
"This may be our last act of defiance in the defense of Equestria. From what I can gather, we are outmatched in armor, strength, and weaponry. If you choose to follow me this time, I can't promise everything will be okay," Twilight started, still sniffling and wiping away her tears. "We will be going up against a trained military force far stronger and more advanced than even that of the Griffon Kingdom. The probability of our success is near non-existent."
"I think I can speak for all of us when I say we're with you one-hundred percent," Applejack said, the others nodding in agreement.
"This is my plan. We'll head back up the way we came, and pray the enemy isn't there. If they are, I've got enough magic right now to teleport us to Celestia's chambers. It's only slightly closer, so I'd like to avoid having to do that. If they aren't we'll head through the east-west corridors in hopes that we can make it to the Vault without running into the enemy," Twilight plotted.
"So basically, don't get seen," Rainbow summarized.
"I think I may be able to help with that," Rarity chimed. "I know a spell that can make things invisible for a short time. I use it when ponies walk in on me designing a new fashion line."
"Perfect. We can use that when we get closer to the Vault," Twilight said. She stepped over to the door, and her friends followed close behind, all of them determined to make it to the Vault. "We're walking straight into the apocalypse."
"We did the same with Discord, and he did not prove insurmountable," Rarity countered quickly. "This is what we do."
"And just in case I don't get to say it later... You girls have been the best thing to ever happen to me," Twilight sniffled, smiling back at the five ponies who'd changed her life for the better. "You've taught me about the most amazing form of magic I've ever been blessed enough to study, and you all mean so–"
"Twilight, we'll make it. This isn't the time for goodbyes," Fluttershy interrupted softly, placing her wing over her unicorn friend. "Let's go."
Twilight pulled open the door and poked her head out to make sure that the enemy hadn't made their way down into the tunnels below the palace. As Twilight cast her light spell, a rumble from above made a little bit of dust fall from the ceiling. Seeing no movement beyond that of the falling stream of dust, she stepped out into the hallway, her friends following closely. They made it up to the main hallways with no incident, though the sounds of fighting and screaming ponies became louder as they approached the hidden door that led down to the tunnels. Twilight opened the door and looked outside and gave the all clear.
Together, they snuck through the castle halls completely unnoticed. Military ponies armed with enchanted spears and the rare few with muskets passed them by, but never noticed them, too busy trying to intercept the enemies and protect the castle and the princesses. But eventually, the six had to enter the throne room to get to the Vault, and when they got close enough, they started to see the enemy. They were massive creatures, about the size of a grown bear, and wore thick metal armor. They walked on two legs and carried strange metal contraptions that belched something from them, which they quickly discovered were a highly effective weapons system that Equestria had no chance of competing with.
Twilight turned to Rarity, "Can you do that spell?"
"I'll try," she responded quietly, powering up her horn. Each of them noticed a pale blue aura begin to surround them, a mild chill accompanying it. If put into words, they would describe Rarity's magic as a sort of void, a blank canvas for her to work with and will things into it. It took a few moments, but the six noticed their bodies begin to turn transparent. Rarity then released the spell, and smiled to herself. "We have about five minutes."
"Keep in close contact. We can't afford to lose each other," Twilight said, flicking her tail and hitting Fluttershy. "Keep your tails swinging. Stay where you can feel someone hitting you with it."
------
Shirska had taken down the three remaining Cabal Legionaries, but hadn't anticipated a second dropship of the heavily armored enemies. He'd made it through an entire battalion of Cabal, though just barely. Now, Shirska was down to three magazines of his thirty-shot auto rifle, a single rocket in his rocket launcher, and only a third of his tank of ether. Aside from that, he had no more usable weapons. However, he had a plan. He'd seen fusion rifles in use, and planned to test Pinkie's against the Cabal in hopes that it could pierce their armor where even his hand cannons failed. If not, then he planned to borrow Applejack's shotgun and machine gun, and just keep running through the weapons of the ponies until there was no other way to fight than with his bare fists.
Shirska took cover behind the stone as the ship dropped off the new combatants, praying that the Harvester's gun wouldn't see him. It was only when it flew off that he dared check what he was fighting. On the other side of the clearing were six Phalanx and a Colossus, with a Centurion and four Psions for added measure. He cursed under his breath and traded his machine gun with Applejack's and his hand cannons with Pinkie's fusion rifle. "I've done this once..." he huffed, feeling the exhaustion of heavy exertion and low ether beginning to set in. "I can do this again."
As the Colossus sped up the barrels of its slug thrower, Shirska pulled up the fusion rifle and held the trigger, feeling its induction coils energizing inside the weapon. When it finally fired, the seven needles of arc energy blasted forth from the barrel of the weapon and punctured the chestplate of the colossus. But the beast still stood, its armor somehow intact even after being pierced by the weapon's fire. It simply turned its gaze upon him with great disdain and brought its slug thrower to bear on him. "FIGHT ME YOU FAT, DISHONORABLE DREG!"
As the first shots from the Colossus' weapon left the barrels, Shirska charged another fusion rifle shot and started moving.
"FIGHT ME!"