Brightspawn

Luna, Discord, Shining Armor, and an unconscious Cadence materialized in the dark. “Not that I’m complaining, but how are we alive?” Discord asked.

“We used Starswirl the Bearded’s teleport spell to flee to the gem caves beneath Canterlot,” Luna said, firing a beam of energy at a nearby gemstone, illuminating the darkness.

Cadence woke up and took a look around. “This place brings back bad memories. Why’d you choose these caves specifically? The Crystal Empire could offer us shelter if we went there instead.” She glanced at Shining Armor, who was still completely brain-dead.

“We have reason to believe that the Crystal Empire is under attack at best, and already fallen at worst,” Luna said. “Also, since the Changeling Invasion, the nightguard have been out looking for the changeling hive. We have found absolutely nothing.”

“I don’t understand what that has to do with anything…” Discord said.

“The Nightwatch are not only renowned for their speed, strength, and bravery in battle, but also espionage,” Cadence explained. “They are the perfect spies, operating when everypony is asleep, able to see everything, hear everything, even see around corners, due to echolocation. If they were all over Equestria looking for the Hive and found nothing…”

“Chrysalis’ knowledge of the caves beneath Canterlot and her choosing to hide you there should’ve been a bigger clue. They live beneath us.” Luna said, heading off towards a mineshaft.

“Chrysalis is dangerous! You don’t know what she’s capable of doing!” Cadence shouted, running after Luna. “This is ridiculous. You’re saving us from certain doom only to land us back in there!”

“We have a plan,” Luna said. She reached a large vertical drop and dove in. “Make sure that Shining Armor and Discord get down here too.”

Cadence took a deep breath and let it go. “What do I have left to lose?” She muttered, scooping up her husband on her back and floating down after Luna.

“Oh don’t mind me, just a stone, flightless Draconequus dragging his stone, flightless feet,” Discord said, jumping into the hole and bouncing against the walls several times on the way down.

Luna landed quietly on the floor of the pit. “Tread carefully,” Luna said, “We don’t know what to expect down here.” Discord landed at the bottom in a loud crash, shattering several gems. The sound echoed throughout the caverns as Cadence dropped down, setting the zombified Shining Armor down rather roughly. “Nevermind,” Luna sighed, peering into a nearby dark hallway. After she turned her head away, several glowing blue eyes peered back.

“Chrysalis! We need to talk,” Luna said, shining her horn like a flashlight into the darkness. There was no response.

“What would you want to talk to Chrysalis for, anyway? She wouldn’t help us,” Cadence said.

“Tranquility plans on wiping out all life in Equestria. This includes the changelings,” Luna said. “Changelings only seek to ensure their own survival. We’re not expecting full cooperation, but at least a fair trade.”

“What kind of trade would you make with that monster?” Cadence asked. “What can she do that can help us in a situation like this?”

“Shining armor is the only thing we have that can stop Tranquility’s magic. He happens to be under Tranquility’s mind control. What other mind control can you think of that we might be able to override it with?” Luna said, stopping to turn and face Cadence. “So, will you do it?”

“Was it that obvious?” Cadence asked, before burning up in green flame. Her pink coat melted away, becoming a hard, scaly black shell. Her man thinned and grew out, turning darker, bluer, merging into a single color. As the Changeling Queen stood to face Luna, hundreds of changelings poured in from each direction. A group of changelings marched in, carrying the real Cadence, bound and gagged.  “So you want some mind control?” Luna nodded. “It will have to cost you.”

“But surely you want Tranquility stopped as well!” Luna cried. “Why should we have to pay? What do we have that you want?”

“While it is true that it’s been difficult to… feast lately, think about how long it took for the nightwatch to find us, if they ever truly did. Do you really think that the Solemn Guard will have a chance? Changelings will always survive.” Chrysalis said.

“Thou are bluffing. Changelings are parasites. Without anything to feed off of, you’ll die off too!” Luna protested.

“Well, that’s true, but you will disappear first,” Chrysalis said. “Of course, I’m not ruling out the notion of helping you. In fact, I’m quite for it. I would be happy to take Shining Armor under my control again. I just require some payment first.”

“Name your price,” Luna said. Chrysalis smiled like a hyena eyeing its prey, circling the Princess of the night with a hunger in her eyes.

“As I said, it’s been so difficult to get a good meal in lately. My price for controlling Shining Armor will be… your personal feelings, Princess Luna,” Chrysalis said.

“Thou are being ridiculous. We have no feelings to give to anypony, what would thou take?” Luna asked indignantly.

“Oh but you do, perhaps without even realizing it. We changelings can sense these things, and it makes us so… hungry. So do you agree? You will get your mind control and I will get my feast,” Chrysalis said, eyeing Luna.

“Very well, but make it quick,” Luna said, immediately regretting it as a swarm of changelings covered her, pinning her down and lifting her head. She turned her gaze upwards to see Chrysalis descending upon her like a starving wolf on a piece of raw meat.

Pain. Sorrow. Hatred. Despair. All of these feelings flashed through Luna’s mind as she felt her very essence being drawn out through her skull, feeding the enormous parasite that was the Changeling Queen. Her wings flared and shut, as if trying to fly away from this terrible feeling. Her legs wiggled, held still by changelings as they watched their queen eat. It lasted for what seemed like hours. Shining Armor watched, emotionless.

The changelings released Luna and she rose on shaky legs. “We fulfilled our part of the bargain,” she said, trying to sound as if there were some shred of strength left in her. “Now we have instructions for you.”

The changelings untied Princess Cadence, and Chrysalis stretched her insectoid wings. “My, that was a nice meal. I haven’t eaten like that in ages. Do come knocking if you ever want to make this deal again. And don’t bother telling me the instructions. I stole them out of your head while you were helpless.” She struck Shining Armor with a powerful blast of green.

Shining Armor’s eyes swirled as he turned to face his attacker. Chrysalis transformed into Princess Cadence, approaching him slowly while increasing the power of her beam. “There there, darling. It’s me, remember? Why don’t you just relax and let your mind go blank?”

Princess Luna restrained the real Princess Cadence, who was fuming with anger with no idea of what was going on. Chrysalis continued.

“There is no Tranquility. There is no light. There is only me. Princess Cadence, your beloved wife.” Shining Armor blinked slowly.

“Ca…dence…” He said. Chrysalis rolled her eyes. Mind control always turned men into buffoons.

“Why don’t you be a dear and walk over to that pony over there. Can you tell me her name?” Chrysalis asked, gesturing towards the real Princess Cadence.

“Ca…dence?” Shining Armor asked. Discord stifled a snicker as Shining Armor approached Cadence. The two met and touched horns. A spiral of light lifted the two ponies off of their feet, wiping Tranquility’s mark from Shining Armor’s body and restoring his color. Chrysalis ceased casting her spell and flew off into one of the side tunnels, followed by her legion of changelings.

“What happened?” Shining Armor asked as Cadence hugged him. “Last thing I remember was my attack on Tranquility’s castle…”

“You failed,” Luna said. “And we brought you back. You’re in the gem caves beneath Canterlot, and Canterlot has fallen. Your sister, your guards, and the palace are all under Tranquility’s control.”

“You have a plan then?” Shining Armor asked. Luna flipped through Starswirl the Bearded’s book of spells.

“This spell here, and it’s our last shot. Normally it requires the Elements of Harmony, but they were lost in battle,” Luna placed the book open on the ground. “So we will have to supply the large amount of magic required.”

“That’s the restoration spell used to free Discord from stone!” Cadence said. “But won’t he just get turned back into stone when Tranquility finds him?”

“Why else would we spend our remaining resources rescuing the only two ponies in Equestria capable of deflecting Tranquility’s magic with force fields?” Luna asked.