“I just don’t understand why you won’t let me go.”

“Dinky, we’ve been through this a hundred times already.”

The sighed response from her adopted older sister only soured Dinky Doo’s already dour mood. The two sat at the dinner table in their Crystal Empire home, their meal growing cold as this contentious argument was heating up. Again. Ever since Princess Flurry Heart had announced her intention to journey down to Equestria in an attempt to save it, Dinky had wanted nothing more than to help. But Sparkler had volunteered before her, and convinced Starlight Glimmer that she shouldn’t be considered. Once Dinky discovered this, the rift between the two Doo sisters only grew wider and wider with each passing day.

“I mean, I’m as old as Sweetie Belle. She got to go. Why won’t you let me volunteer?” Sparkler, the weariness of this conversation having already played out incessantly over the last two weeks, rubbed her temples. She loved her little sister, but this issue was beginning to drive her up the wall.

“Dinky, you saw what kind of condition Sweetie Belle returned in, right? What condition all the other mares rescued are in? What if that happens to you?” She tried reaching across the table to take hold of the iris purple pony’s hand, but she jerked it away as Dinky abruptly stood up. The blonde-maned mare’s face was still scrunched up in frustrated anger and, though Sparkler knew she was partly responsible for it, she knew that there was another, far larger reason behind this.

“What?! Are you saying I can’t cut it? Is that why you won’t let me volunteer for heading on the princess’ mission?”

“No. What I’m saying is that I don’t want what happened to them happening to you.”

“I can take care of myself, Sparkler. I’m a grown mare now!”

“Then why don’t you start acting like it?!” Sparkler snapped; her limit reached as she stood to match her little sister. “Try seeing this from my perspective, won’t you? We both lost Mom. I don’t want to lose you too. She wouldn’t want you risking your life, either.”

“She’s not your mom!”

The moment the words escaped Dinky’s mouth, she regretted them. Her hands shot to her mouth in some childish attempt to catch them, but it was too late. Sparkler froze. Her hands twitched as her arms fell limply to her sides. Her eyes stared wide in shock at the younger unicorn, tears threatening to escape. For what seemed like an eternity, the two simply stood there, shocked silent at the outburst.

Dinky was one to finally break the silence. “Sparkler… I… I’m-”

“No.” Sparkler cut her off, her head dipping down to hide her eyes behind her fringe, though the tear streaks rolling down her cheeks were unmistakable. Her tone was soft and broken, but firm enough to hold Dinky in place. “I think you’ve said enough.” With that, the older sister solemnly walked out of the dining room before running up the stairs.

“Sparkler, wait!” Dinky cried out at the bottom of the stairs, but the slam of a door ended any apology she was about to attempt. Guilt welled up within the young Doo mare as she sat down on the bottom step. She didn’t know why she said what she said. It was a random outburst of anger, but she didn’t mean to go that far. Adopted or not, Sparkler had been an amazing sister to her. She just didn’t want to be babied like this when her, no, their mother was out there.

She was unsure how long she sat there, but eventually Dinky stood up. Her guilt-laden sorrow had melted away, replaced with determination.

“I’m sorry Sparkler,” she whispered as she moved back into the kitchen, cleaning up their forgotten dinner. “I’ll make this right. I promise.”

“Hey Rumble. Another late-night training session?”

“Yeah, if that’s okay?” Rumble feigned a bashful look as he spoke to the two guards protecting the training grounds. He chose this particular night as these two guards – a steel-blue crystal pony mare named Chrome Spear and an earth pony refugee named Caramel – were pretty lenient when it came to him training late into the night. Rumble pulling an all-nighter in combat training wasn’t anything new.

“Are you sure you should be pushing yourself this hard?” Chrome asked, concern flashing on her face. “I mean, you’ll no good to anypony on the mission if you’re exhausted before even getting called up.”

“Ah, colts will be colts.” Caramel waved off her concerns. “Besides, his brother Thunderlane pushed himself to the extreme a lot of times trying to become a wonderbolt, Ain’t that right, Rumble?” The grey pegasus nodded, thankful a Ponyville native like Caramel had volunteered for guard duty.

“Alright,” Chrome sighed, knowing she was outnumbered. “Just… just pace yourself, okay?” Another nod from the young stallion and the two let him in. He thanked them as he walked inside and kept a casual pace towards the training field for about a minute after the doors closed.

Once he was certain they had returned to their duty as guards, Rumble got to work. Spending most of his days since the announcement of the princess’ mission training for combat had its advantages. One was getting in despite the grounds being temporarily closed. Another was, as her made his way into the weapons storeroom, was that he had keenly observed the professional soldiers unlocking the cabinets containing the real weapons. Trainees like himself and Pound Cake were only allowed wooden training swords and weapons, but opening that cabinet full of crystal-bladed weapons felt like he was a young colt entering Sugarcube Corner for the first time.

Unzipping the duffel bag he normally brought his training gear in, he shoved a set of light crystal armour and throwing knives into the bag. Alongside said acquisitions were around three days’ worth of rations and a picture of his family from happier days. Zipping it back up, he then picked up two single-hand crystal swords and headed back into the open space in the middle of the square building. Though a late-night training session had been the cover story to get in here, that didn’t mean he was going to pass up the opportunity to sharpen his skills. As he swung the swords, gaining a sense of their weight and how best to handle them, he made the conscious effort to vocalise his strikes. This helped sell his lie to the guards outside. Another hard swing with both swords helped solidify the next part of his plan. Stabbing one sword into the ground, her grabbed the straps of his bag with his free hand, then spun in place to build momentum. With a big shout, he swung the sword while leaping in a spiral. He then let go of the bag, the momentum of his swing enough to fling it up onto the roof on the opposite side of the entrance. To mask the noise, he then followed through with another attacking routine.

Another five minutes of actual workouts and he decided that had been enough time selling it. As quietly as he could, he took flight and gently placed the now-sheathed swords next to his bag on the roof. Landing back in the training area, he grabbed a towel left from earlier in the day and wiped down all the sweat before making his way towards the entrance. Knocking on the door, he then opened it to the looks of the guards; Caramel surprised, while Chrome’s was more suspicious.

“Rumble? Done already?” Caramel asked.

“I just forgot something from home. Is it okay if I go grab it and come back? It’ll only take a few minutes.”

“What sort of something?” Chrome asked, eyeing the pegasus.

While he had hoped these two would just accept his reason, he had planned for this contingency. “I picked up some weighted wristbands and leg braces from the market the other day and had been wanting to try them out tonight. I haven’t brought them along before because I didn’t want to make the others jealous.”

For a little while Chrome scrutinised him, though to Rumble it felt like she was staring a hole through him for hours. Finally, she relented with another sigh. “Fine, but make it quick. Our shift ends in an hour and I doubt anypony else is going to like you being inside this late.”

“Thanks Chrome.” Rumble replied with an enthusiastic grin, though he followed it up with a theatrical yawn. “I’ll be back in a bit.”

He took flight, heading in the direction of the house he was leased. Button Mash had been with him initially, but moved out to live with Sweetie Belle once their relationship grew more serious. He kept his altitude low, to avoid any other guard patrols seeing him and thinking he was a monster that had snuck through. Once he was sure the guards couldn’t see him, Rumble banked hard and came back towards the training grounds, but from the other side this time. Landing softly on the roof, he slung the swords over his shoulders and grabbed the bag before fluttering down to the road below.

“Like taking candy from a foal.” He murmured to himself.

“Rumble?” The firm tone made the pegasus jump, but strangely it was one he recognised. One that didn’t belong to anypony on the guard. He slowly turned around and standing behind him was his old schoolmate Dinky Doo.

“D-Dinky? W-What’re you doing out this late?” He failed quite miserably in hiding the nervousness from his voice. The blonde unicorn levelled a flat stare at him.

“I could be asking you the same. Or perhaps, I could be asking you why you’re apparently stealing from the training grounds.” That golden stare cut him deep, and running now would look even worse. She could just tell on him and then there’d be no chance he’d be able to sneak out.

“Well,” he sighed, but stopped when he spotted Dinky with her own duffel bag. “…I’ll tell you why if you tell me the same.”

“Excuse me?”

“Why are you out here with a duffel bag of your own, huh? I won’t spill unless you do.” He jabbed a finger at her, her stern demeanour cracking somewhat.

“W-Well, I…” Dinky stuttered before sighing. “Okay, fine. I was going to sneak out.” She then leaned back in and jabbed her own finger back at him. “But you were going to sneak out too, weren’t you?”

“…Fine, yes.” He grumbled. “Look just… wait. You’re sneaking out? …Why?”

Dinky sighed again. “No offence to the princess, but I’m tired of waiting for them to find my mom, and as much as I love her, I can’t stand Sparkler keeping me out of the loop. All I want to do is help find Mom, and I just…”

“No, no. I get it.” Rumble interrupted, gaining her surprised attention. “I can’t wait any longer either. I thought the princess or Starlight Glimmer would choose me to help, but it seems they don’t need my help. But they haven’t found my mom yet, or Thunderlane, and I don’t want to waste another second stuck up here while they’re down there suffering.” The sound of ponies approaching spooked both of them and Rumble led them down a couple different streets until the voices faded.

“Okay,” Dinky asked in a hushed tone. “If we’re both trying to sneak out, then why not just go together? That way, we can watch each other’s back and do things either of us couldn’t alone.” Rumble thought this over. Part of him wanted to shake her off as he felt he’d be better alone, and that she would just slow him down. But he was well aware he could be hot-headed, and having another pony along on the journey would help immensely. He also noticed a small silver ring worn at the base of Dinky’s horn.

“Okay, let’s go together then. What supplies do you have?”

Dinky unzipped her bag and looked inside. “I’ve got about four days’ worth of food, uhm… about fifteen bits, aaaaaaand… a couple of spell scrolls Sparkler was practising in case she got picked for the mission.”

“Spell scrolls? Which spells?”

“Uhm, I think she had a beam attack, cloud walking and… teleportation, I think.”

The gears in Rumble’s brain started spinning even faster. “That’s perfect. You can teleport us out of here, then we can make our way to Ponyville. Even if our families aren’t there, we could find some clues as to where they’ve been taken.”

“Rumble, I’ve never tried any of these spells. I don’t know if I can do them at all.”

The young stallion took the unicorn by the shoulders and looked her in the eye. “Dinky, look at me. If there’s one thing I learned from my brother, it’s that if you don’t push yourself, you’ll never know what you’re capable of. Remember, this is for your mom.”

Dinky knew Rumble was using her mom as motivations for his own desires, but she still searched through the bag and pulled out the scroll. She took a moment or two memorising the requirements of the spell. It still seemed tricky, and she wasn’t as magically inclined as other unicorns, but it still seemed doable. She just needed to focus on a fixed location. A close and easy target was the Galloping Gorge. Only a few kilometres to the south, she remembered her Sparkler and their mother going on a camping trip there once. With their old campsite pictured firmly in her mind, Dinky began channelling her magic. A dull golden hue enveloped her horn as her magic built and built. She gripped the strap of her bag tightly with one hand before taking Rumble’s with the other. Ignoring the odd look on his face, she poured all her focus onto the spell and, once she felt she was ready, cast the spell.

In an instant, Rumble and Dinky Doo disappeared.

“Okay… okay, you can do this.”

Lyra motivated herself softly as she once more stood in the cell that housed the entrance way to the fleshy caves below Canterlot. The same cell that held the buxom older mare, whom the mint unicorn had learned was Sluttershy’s own mother. Putting aside her feelings on that, and how unsettling it was clambering below her ever-gushing cunt, she made her way into and down the stairwell. Her pace was quicker this time, as she didn’t want to spend any more time than absolutely necessary. Arriving in the caves, filled with the lustful moans and cries of Celestia-knew how many mares, she activated her invisibility and journeyed further into the depths.

The further she went, the wetter she grew, and the more uncertain Lyra became that she could do this. Soon enough, there appeared a four-way fork in her path. Not wanting remain in one place for too long for fear of discovery, she chose the tunnel to the far right and hurried inside. The tunnels were illuminated well enough, though how Lyra couldn’t say, but this particular tunnel grew dimmer the further she trod. Finally, some light returned at the end of this passage, but the slave pony didn’t like what she saw.

There, fused to the wall was a massive off-grey globe with an ever-slickened vagina about a metre tall. Two head-sized breasts were perched atop this sphere of flesh, with tubes pumping what must’ve been gallons of some liquid into them. The larger orb swelled less than an inch with each injection, but from the sound of it, Lyra could only assume it was sperm. She’d spent decades drowning in it, she was fairly certain she knew it when she heard it. But it was the clit that held her attention, and fears. For the clit was actually the head of a mare. The head of a mare that Lyra knew.

Twilight Velvet.

The elder unicorn couldn’t see her or call out to her, her eyes and mouth covered in skin as if she were a living mannequin. Despite not having a mouth, she still moaned as the labia adorning the front of what was left of her body winked. The pumping paused, but only for a moment. Lyra watched on in horror as, with a loud moan, Velvet threw her head back and out of the pussy poured over a dozen infant monsters. Separate tendrils connected to the roof collected them one by one as the pumping resumed, spurring the corrupted unicorn to vocalise more pleasure.

Lyra didn’t stick around to see what happened next, turning and running out of the tunnel. She didn’t stop until she was back out at the crossroads. Her panic urged her to teleport back to the relative safety of the castle, but she physically slapped herself to hold those thoughts in check. It probably wouldn’t be long before Talivra returned from subjugating the Storm Kingdom, and if Lyra didn’t have something more substantial to show her, there was no guarantee she wouldn’t fuck Lyra back into the mindless hell of ecstasy.

Taking a few deep breaths, she stood back up again, only now noticing how freely the liquid bounty of her own bosom was flowing. Milk trickled down along the underside of her chest before dripping onto the ground. It was only a matter of time before something saw or smelled that, and Talvira’s protections only extended to the guards in the castle itself. Knowing she couldn’t stay there, Lyra chose the centre left tunnel and steeled her nerves as she went in.

This tunnel remained as well-lit as the rest of the caverns, but the echoing of carnal moans died down in this section. She soon found herself coming towards a large door. There was no handle; only a keyhole. But taking a peek through, she concentrated and teleported inside. The chamber resembled more of a laboratory, though the floors and most of the walls were still covered in that fleshy substance. One wall was covered in metallic, scientific equipment. Some of it Lyra recognised from her days back at Celestia’s School for Gifted Unicorns, others she couldn’t begin to guess their function.

And over to her right, more horrors. Floating in three large tubes were her foalhood friends Minuette, Lemon Hearts and Twinkle Shine. The three unicorns had their wrists and ankles bound in that fleshy gunk, which was connected to the roof and floor of the tube. A second tendril opened up into a mask that covered the entire face of each mare, while a third was buried snugly in their snatch. The fact the three appeared unmodified was a welcome relief for Lyra, however small. She walked forward, resting a hand upon Minuette’s tube.

“I’m sorry I can’t save you three now,” she whispered. “But hang in there. My special somepony, Bonbon… she’s coming to rescue us.”

“Oh really?”

Ice flooded through Lyra’s veins at the voice from behind her. Slowly, the mint mare turned around and there, with a predatory grin spreading across her muzzle, was Midnight Sparkle. She checked and found the invisibility spell was still active. And yet, taking a few steps back towards the exit, the corrupted alicorn’s teal eyes following her movements.

“How very peculiar to find you down here,” she stated, matching Lyra’s pace as she approached her old friend. “Down in my private lab, aware enough to speak normally, and not begging for cock. How did you end up here, in such a state, Lyra?”

Lyra chose not to answer and instead teleported. She landed in the entrance hall of the castle, the shadows of the afternoon growing long through the windows as the obscene lights were being lit. But no soon had she stood up than Midnight teleported in right next to her.

“Hold still, you little-”

Lyra jumped once more in a flash of golden light. This time she arrived in the west wing of the castle, and immediately started running. She turned the corner just as Midnight popped into the hallway and kept moving, not looking back to see the former princess taking flight to chase her down. She took a sharp right and bumped into something soft, falling to the ground. Looking behind her, she saw Midnight rearing up on her serpentine tail, fangs bared.

“Now I’ve got you.”

“Stop!”

Both Lyra and Midnight froze, the unicorn only realising her pursuer was physically frozen from something other than fear. She looked in front of her, and up to see the off-yellow form of Queen Sluttershy.

“Bow.”

With one word, Midnight was forced to prostrate herself before her former friend. Lyra scrambled to her feet before taking up the customary pose all maids stood in before their rulers.

“Midnight,” Sluttershy asked, keeping her tone level and her firm Stare on the corrupted alicorn. “Would you like to explain why you are chasing a member of my love’s harem through the castle?”

“S-She snuck into my private laboratory,” Midnight stuttered involuntarily. “S-She must be a spy for our enemies. P-Please, my Queen. Allow me to-”

“I don’t think Talvira would be pleased with you tinkering with one of her chosen maids. Neither am I, for that matter. I will deal with her myself.”

“B-But my Queen-”

“But nothing!” Sluttershy raised her voice. “Now get out of my sight unless you wish for my love to give you an even harsher punishment.” Midnight growled in frustration, but ultimately teleported out of sight.

“As for you…” Sluttershy now turned to Lyra, her seemingly ever-erect cock head mere inches from the unicorn’s muzzle, “have some explaining to do.”

“I, I’m sorry, your highness. B-but I-” Her stuttering was cut off when the corrupted yellow pegasus placed a hand firmly on the unicorns’ shoulder and guided her forward.

“I’m sorry, Lyra,” Sluttershy explained in a kind yet firm tone, gently pushing the would-be spy right up to the doors of the royal bedroom. “But I think you should spend the night in our bed. That way, you can report your findings to me in a safe and… intimate… way.”

Midnight reappeared in the central chamber of her caverns with a roar of rage, drowning out the sounds of pleasure from her victims. Her anger overflowing, the mistress of magic snapped her fingers and, at once, all tentacles doubled their speed and intensity. The chorus of ecstasy escalated in volume as the alicorn slithered irritably slithered back towards her lab.

“Cozy Glow!” She bellowed. Within minutes, the young pegasus pupil flittered through the tunnels and landed nervously before her mentor.

“Yes, my mistress?” She asked with a low bow.

“We had an intruder. Why didn’t you alert me?”

The young mare squirmed in what Midnight could only assume was fear. “W-We did? I… I’m sorry, mistress. I was just preparing for when we finally unveil our plan.”

Midnight exhaled loudly through her nostrils. “Then speed that task up however you can. Our guest managed to infiltrate my lab. I’m unsure how much she saw, but I don’t want to take any chances.

“We’re moving the timetable forward. You have a few days, not weeks, to be ready.”

Author's Note

Things are heating up all across Equestria. For those wondering, Rumble would've done this sooner or later had he not been voted for in the main chapters. With him only just missing out this time, I felt it was time to pull the trigger on him going rogue.
Dinky was a new addition to that plan, however, and not only does Rumble get a partner, but it also helped flesh out why Sparkler, of all ponies, was an option t bring on the mission, and Dinky wasn't.

Incidentally, any focus on Rumble and Dinky from this point on will be in the main chapters, given they do have their own stat blocks. Stat blocks that look something like this;

Rumble:
Purity: 2/2
Will: +1*
Strength: +4 *
Defence: +2*
Speed: +3
Magic: +1
Items:
Crystal Sword x2: +1 to Strength Checks
Light Crystal Armour: +1 to Defence Checks
Food Rations x3
Family Picture: Once per chapter, reroll Will Check

Dinky Doo:
Purity: 3/3
Will: +3
Strength: +1
Defence: +2
Speed: +2
Magic: +3*
Items:
Horn Ring: +1 on Magic Checks
Spell Scrolls: Advantage on Magic Checks in relation to Beams, Cloud Walking, and Teleportation
Food Rations x4

And things are heating up in Canterlot. Lot of moving parts to this story now, and there will be more, given Pinkie's now restored.

As always, thank you for reading and I hope you enjoyed it!