'...You're going to have to explain that when we have more time,' Twilight said telepathically. 'Anyway, I just wanted to let you know I had arrived. We know Chrysalis has some sort of trap in place, so I'll need to stay focused on things here until I'm done. I'll make sure to contact you as soon as she's dealt with.'
'Very wise,' came Sombra's response. 'I shall ensure the situation here is under control by the time you return. Although, I must admit that I never expected to enjoy myself this much while helping others.'
Twilight let a smile spread across her face as she returned to the task ahead of her. Looming above her and her friends was the twisted castle where Queen Chrysalis awaited them with her hostages and changeling army. Twilight looked at her friends and her smile grew. Chrysalis had used tricks and monsters to harass them every step of the journey but to no avail. Twilight's Dark Magic had let her detect the Changelings and see through their tricks, as well as making short work of the beasts they crossed paths with. As a result, she and her friends were all unharmed and in high spirits, ready to face the Changeling Queen and rescue the three captured fillies.
"We have to hurry," Twilight said to the group. "The Secretariat Comet will be passing overhead soon."
"And that's when the magical surge happens?" Applejack clarified.
"Yes, although, technically, it's already started," Twilight explained. "The Secretariat Comet radiates magical energy that empowers the creatures of Equestria as it passes overhead. However, when it passes through the Horse Head Nebula over Equestria it will be the biggest astrological conjunction in millennia and the magical surge will reach it's peak when that happens. Fortunately, the surge should taper off rather quickly after that, according to Som- er, something I read."
"I-I don't suppose we can just wait until after the Changelings' power surge wears off?" Fluttershy asked.
"This is Chrysalis we're talkin' about," Applejack said firmly. "She left Twilight and Princess Cadance ta starve underneath Canterlot. There's no tellin' what she'll do ta my sister and her friends if we don't make her deadline."
As they approached the entrance to the castle, Fluttershy whispered, "The whole place looks abandoned... Maybe they all left?"
"I called this back in Ponyville," Rainbow Dash replied. "A trap!"
"Doesn't she have a whole army?" Applejack asked rhetorically. "Ah know Twilight captured some of them in Ponyville, but where the hay is everypony else?"
"They have to be inside the castle," Rarity insisted. "There's no way she would bring us here and be gone!"
"Oh! Oh!" Pinkie Pie piped up, "I bet they're all waiting for us right behind the front door! Thousands of Changelings, ready and waiting, poised to strike!"
"Gee, I wonder why that makes me want to open the door less," Rarity said, shooting an annoyed look at her hyperactive friend.
"Th-Thousands?" Fluttershy repeated in a terrified whisper.
Before any more could be said, the front door of the castle began to creak slowly open. Exchanging nervous glances, the six mares crept inside, only to freeze at what they saw.
Stairs. Not just going up and down, but stairs going sideways and backwards and upside-down, as well, each leading to a different doorway. It was like some sort of optical illusion brought to life, stairways and doors existing at impossible angles.
"Wow, under attack by stairs," Rainbow Dash said, wide-eyed. "I can feel my head hurting already."
The others' attention was drawn when Twilight let out a pained groan. Rubbing her horn with one hoof, she said, "There's so much Dark Magic in this place, it's like the air's filled with it. We need to be extra careful from here on out."
As if to confirm her words, Chrysalis' voice suddenly echoed throughout the castle, "Open the doors, little ponies. Behind one you will find me! However, the others all have a vast array of surprises for you!"
"Stick together girls," Twilight said. "It'll take longer, but with all the Dark Magic in this place, I won't be able to tell if somepony get's replaced by a Changeling."
One by one, they worked their way through the doors, opening them, only to slam each in the face of one of a myriad of horrifying creatures. Finally, Twilight opened one, only to find a barrier of Dark Magic.
A voice started to emanate from the barrier, but by that point, Twilight was far to irritated by the delay to listen. Thrusting her horn into the barrier, Twilight closed her eyes in concentration and simply pulled, drawing the magic out of it and into herself. Opening her eyes, now glowing with Dark Magic, Twilight gazed into the room beyond.
In the middle of the room was Queen Chrysalis, standing over the three kidnapped fillies who were enveloped in a Changeling cocoon. Behind her stood the rest of the Changelings. While Pinkie Pie's estimate may have been an exaggeration, the army was still dozens, if not hundreds, strong, far outnumbering the group of ponies.
"Apple Bloom!" Applejack called out upon spotting her trapped sister. Glaring at Chrysalis, she demanded, "Let her out of there now, Queeny!"
"Sweetie Belle! We're coming for you!" Rarity called out as well.
While the two fillies grinned at the sight of their sisters, Scootaloo looked down and mumbled, "It must be nice to have a big sister..."
Knowing things would not get resolved so peacefully, Twilight still gave the Changeling Queen one last chance. "Okay Chrysalis, we're here. We made it before your deadline. Now, hoof them over... or else."
"Or else what?" Chrysalis sneered. "You'll do to me what you did to my children in Ponyville? After that, you're lucky these three are still unharmed. I had half a mind to simply leave you their drained husks as punishment. As it is, I have been thinking of how I should punish you, and after watching you for the last three days, I think I have just the thing." Chrysalis' horn began glowing as she suddenly aimed it right at the imprisoned fillies. "Surrender yourself, Twilight, or I will seal this cocoon so that nothing can get in or out... even air."
"Ya wouldn't dare!" Applejack shouted, tensing up along with the rest of her friends.
For Twilight, however, the ultimatum was the final straw. Firing a blast of Dark Magic at the Changeling Queen, it was only when Chrysalis grinned and immediately counterattacked that Twilight realised she had been goaded. Nor did she understand what was wrong until their attacks collided and Chrysalis' magic tore through hers. Eyes widening in shock, something Sombra had said popped into her mind.
"You've seen the raw power that Dark Magic can bring to bear, but brute force was never its intended purpose. Light Magic will always be able to overpower Dark Magic in a fair fight."
Chrysalis' attack struck Twilight directly, sending her crashing back into the wall. As her minions swarmed Twilight's friends, Chrysalis stalked towards the fallen unicorn. "What's the matter? Didn't know about Dark Magic's little weakness?" The Changeling Queen taunted. "Dark Magic is quite dangerous, but only if the being wielding it is incredibly powerful or uses it cleverly."
"How..." Twilight gasped as she struggled back to her hooves. "You're a creature of Dark Magic..."
"Oh, so a unicorn can use Dark Magic, but a Changeling can't use Light Magic?" Chrysalis scoffed. "What kind of Queen would I make for the Changeling race if I couldn't use the magic of the ponies we impersonate?" Slamming Twilight into the wall again with another burst of magic, Chrysalis stood over her with a sinister grin. "As fun as this has been, I think it's time to end this. And after I finish you off, I think I'll have your little friends for dessert. And the best part is, you lost your advantage because of your own arrogance. Goodbye, Twilight Sparkle."
As her enemy prepared for one final attack, Twilight's mind was awhirl. 'Is this the end? My friends, I have to save my friends... And Sombra, will he go back to the way he was before? What will happen to Equestria if nopony knows he returned? I can't die here... I can't...'
I won't die.
Sombra grinned as he listened to the celebration going on outside the castle. The Secretariat Comet was already passing overhead and the magical surged would recede by the morning, returning the cockatrices to normal. Proceeding to the throne room, he found Spike already explaining what happened in Ponyville to the princesses. He stepped into the room, intending to contribute to the conversation when something stopped him short.
I won't die.
'Twilight?' Sombra asked telepathically. The voice in his mind had definitely been hers but something had sounded off.
However, the response he received was not in the form of words. Conflicting emotions flooded his mind. Terror and eagerness. Excitement and sorrow. Fury and joy. And throughout it all, a splitting pain that had him pressing his forehooves to his head.
"Black Knight, are you alright?"
As the pain subsided, Sombra looked up to see Spike and the princess standing over him, looking worried. Pushing himself back to his hooves, he said shortly, "Twilight is in trouble."
"What do you mean?" Spike asked worriedly. "Did something new happen?"
Turning Sombra galloped out of the room, saying, "She's facing Chrysalis and something went wrong. We need to get to her aid immediately."
Swooping down in front of him Celestia said "Stop and think, Black Knight. There's no way of knowing for certain that anything has gone wrong, and even if it had, you'd never reach her in time by hoof."
"She and I share a telepathic link created by Dark Magic. I know she's in trouble," Sombra insisted. "We have to reach her as soon as possible."
"A telepathic link?" Luna mumbled, gaining a thoughtful expression.
Frowning, Celestia nodded. "I can reach her fastest by air, and I can take Spike with me. Luna, you and Black Knight wait here, just in case anything else happens to the city while I'm gone."
"But-!" Sombra tried to protest.
"I'll bring Twilight back safe, I promise," Celestia said, before scooping up Spike and taking off.
Watching her fly off, Sombra gritted his teeth in frustration at his helplessness in the situation. "Twilight..." He whispered. "Please be safe."