“Time for your cooldown,” said Twilight Sparkle, turning down the speed of the treadmill to a slow walk. “You did very good this time. A point zero three improvement over yesterday and a full four percent better than last week. I’m so proud of you, Celestia.”

For her part, the big white alicorn could only grunt in response. The muzzle gag that was fastened to her continued to be as efficient as ever at destroying her ability to make intelligible sounds and now, some six weeks after Twilight had trapped her in this dairy of horrors, she had simply given up trying.

Slowly, the treadmill ground to a halt, and Celestia began to feel the relief of cool water being sprayed over her body. As much as she was loathe to admit it, Twilight had been taking good care of her. The only problem was, Twilight wasn’t acting like she was taking care of a fellow pony, not even a fellow pony that she had taken against their will. Twilight was acting like she was taking care of livestock.

“Good girl,” Twilight praised, running the shower head all along her cow’s body, making sure that every drop of sweat from her milk animal’s workout was flushed away, leaving only clean skin and fur in its wake. It had been a lot of hard work for both of them over the past month and a half, but things were about to change and make things much easier.

“There we go, all clean and dry,” stated Twilight when she was finished with the task of cleaning Celestia after the second of her three daily exercise periods. “Let’s see how those udders are doing!”

The chipper and cheerful voice of her captor was a stern counterpoint to the dread Celestia felt at the repeated humiliation of having her teats fondled yet again by Twilight’s magic. The purple aura surrounded a section of Celestia’s flesh, squeezing and rubbing as the younger alicorn coo’ed in delight at what she found.

“Oh, nicely engorged. You’re turning into quite the good milker,” Twilight commented, and Celestia could see a drop of her own milk floating up to Twilight’s tongue for a taste. “We’d better get all that fluid out of you before it starts to hurt.”

Celestia couldn’t help but thrash and complain in protest at what was about to happen, but like every other time she’d tested her bonds, they held firm. Even worse was the collar Twilight had fitted her with the other day. A leather collar that turned any louder noises she made into the lowing and mooing of a dairy cow in the field.

“Easy girl,” Twilight said, tightening the harness around her cow’s body so she would not be able to avoid the milking and stimulation tools. Immobilized, the milk animal was unable to thwart the quick fastening of the suction lines to her nipples, or the progress of the stimulation rod up into her vaginal canal.

With the flip of a switch both devices turned on, pulling creamy nectar from Celestia, while stimulating her pleasure centers to increase the yield. The solar alicorn’s vision grayed out as the combined assault took hold, the beat of the pumping mechanism like the pounding of her heart as the rhythmic pulls on her teats and the steady thrusts of the piston inside her drove her to a quick orgasm and causing fresh milk to fill the receiving tanks near to bursting.

“Yield is up as well. You know, I think you’ve earned a bit of a reward,” Twilight stated afterward; and Celestia’s eyes popped back open as she felt the straps of her muzzle loosen and then pull free. “Instead of me pumping you full of food, let’s try a feed bag today.”

“Twah… Twilight,” Celestia said softly, aware enough to keep her volume under what the spell on her collar would trigger at. “Please… you have to let me go.”

“Silly Celestia. You know I can’t do that. Not until my friends ascend and are just as immortal as I am,” Twilight replied, running a hoof along Celestia’s cheek and making sure that the rest of her bridle was as secure as ever. “Rainbow Dash and Rarity are already showing positive effects.”

“Twilight, please. Let me go. No one needs to—Moooooooooo,” came from Celestia, surprising her.

“I can trigger the collar whenever I want as well. I’d hoped that you would have realized your position by now and gotten used to it, but I guess not. Starlight?” Twilight said, and Celestia felt a chill as Twilight’s student came into view.

“All set,” Starlight replied, a pair of green gems held in her aura with her eyes steadily boring into Celestia’s. “You know Twilight, when you told me what you were doing, I almost didn’t believe it, but then I thought on how many unicorns were just as powerful as you were back then. How many of them had made their own great contributions to Equestria, and suddenly everything made sense.”

“I know. How are your milk infusions doing?’ Twilight asked, deftly taking the gems from Starlight Glimmer and inserting them one at a time into Celestia’s ears, where they stayed as if glued in place without adversely blocking Celestia’s ability to hear.

“Great, I’m already stronger than I ever was, and those little gems should help you keep Celestia firmly under control,” responded Starlight, adding, “Everything is ready for tonight, by the way.”

“Excellent. Anyway, time to eat, Celestia,” Twilight noted, strapping a feedbag to Celestia’s bridle and giving her no choice but to start munching on the sweetened oats the bag contained. A munching that stopped as a voice began to speak to the harnessed milk animal.

“You are a cow. Your milk will save many lives. Being milked is good. Being milked gives you pleasure. You are a cow,” came the voice of Starlight Glimmer, and as the words repeated Celestia remembered where Twilight had originally found her student and what she had been doing there.

Celestia’s wail of despair was translated into a long loud low as she realized that Twilight wasn’t just treating her as a milk animal, she was now actively trying to actually turn her into one.

“Sister? Are you in here, sister?” Luna asked, as she carefully ventured into the nondescript building just outside of Coltsonville. It had taken her weeks of searching, but as Luna spotted one of Celestia’s golden horseshoes, it looked like this particular anonymous tip was about to bear fruit.

“Celest—” Luna began, before breaking off wordlessly as a dim, motion sensing light came on to reveal the bound and bridled body of Celestia, who was sleeping standing up in some sort of support harness. “By the Stars, what’s happened to you?”

The big white mare woke to the gentle touch of her sister as Luna unstrapped her muzzle and pulled it and an attached bit free, and entle blue magic probed around the bridle that remained to keep Celestia’s magic bound.

“Apologies sister, I am having trouble removing… this infernal device from you,” Luna grunted, trying and failing to get the magic blocker off of her sister. “I will simply have to get you out of here first.”

“Twi… Twilight,” Celestia whispered, even through the murmuring in her ears telling her to be good, to obey, that being milked was her destiny.

“She is safe. In fact, t’was Twilight who received the tip that you were being held here,” Luna replied, parting her sister’s hobbles through main force.

“Trap,” was all Celestia managed to think to say, even as a collar on a chain leash began to levitate up behind the lunar alicorn.

“Eh?” was all Luna had time to say.

“TRA—MoooooOOOoooooo,” Celestia blurted out, her collar transforming the word even as her voicebox gave them.

Only Luna’s tilt of the head in curiosity saved her from immediate capture as one limb of the collar hit the side of her neck instead of cleanly encircling it. The impact sent the ensorceled device spinning off to one side and Luna whirled to face her attacker, horn and hooves at the ready.

“Face me, knave!” came the trumpeting challenge of a mare determined to save her sister.

“Stand down and surrender,” said Starlight Glimmer, stepping out of the shadows with a halo of bondage gear floating around her. “This doesn’t have to hurt. Just let me harness you up and you can live a life of ease and comfort dedicated to serving the ponies of Equestria.”

“What have you done to my sister?” Luna demanded, not backing down a whit.

“Did you know her milk can make a pony immortal? Ponies like me, or Sunburst?” Starlight asked, not backing down a bit either. “Or any one of the deserving ponies who have earned the right to become alicorns. Not just Celestia’s chosen few.”

“Starlight, let my sister and I pass. I will not ask thee again,” Luna said, eyes narrowing. Starlight was the true threat, not the bindings she held, was Luna’s assessment, and she made her plans accordingly.

“If there were two alicorns giving milk, the process would go twice as fast,” Starlight said, and her smile hinted at the cruelty it had held when she ruled Our Town. “Everypony would be equal, all the sooner.”

“No,” Luna whispered, and with a breath launched her attack.

Starlight had fought the Element of Magic to a standstill and so sidestepped Luna’s expected initial blast while launching a dizzying array of cuffs, collars, shackles and locking tack at Luna from all angles in response. Back and forth the fight raged at point blank range. The only care either combatant seemed to have was that neither dared to aim anything at the form of Celestia, still held in place by the tethers on her harness and the magic seal on her bridle.

After several minutes, the battle was over, with Luna’s horn nestled in the hollow of Starlight’s throat, and daring the unicorn to even try to continue the struggle, on pain of death. Nor had the Alicorn of the Night emerged unscathed either.

Both of Luna’s forehooves were bound together by a set of hobbles, and a chastity belt with twin plugs had fastened its way around Luna’s hips. Even now, the darker pony shifted her hips in an attempt to settle the invading shafts that had been driven home in an attempt to disrupt her spellcasting.

“Remove yon bridle from mine sister, and you may yet live,” Luna growled, not entirely in anger.

“She can’t,” said a voice, from behind Luna. One that she recognized. “But I can.”

“You!” Luna demanded, quickly turning her head to face the newcomer. Just in time for her vision to register the onrushing bridle that went over her nose and horn, locking away her magic and making her a captive as well.

“Me,” Princess Cadance calmly answered, taking a moment to finish locking Luna’s bridle and fastening her hobbles to the floor. “I would do anything to save my Shining Armor.”

“You cannot be doing this!” cried Luna, trying and failing to free herself. “I am thy friend!”

“And Shining Armor is my husband,” Cadance countered, and she lifted a harness lifted in her pale blue magic to settle around her own body. “There isn’t anything I wouldn’t do for him. Could you give me a hoof here, Starlight?”

“How long have you known?” Starlight asked, eyes wide even as she began the task of binding a third alicorn princess.

“You betray us all!” shouted Luna, jerking her body upwards against the chain locking her forehooves to the floor and failing.

“Don’t bother, Luna,” Cadance advised, dipping her head in order to accept her own bridle, complete with nullifying ring. “Twilight designed those bindings to hold an alicorn five times as strong as Celestia. She always was good at making plans.”

“Twilight?” Luna asked, incredulous. Celestia’s nod of affirmation was the final blow, and Luna slumped in surrender. “This is to be our fate then? Naught more than animals, kept alive for our milk? Kill me and have done with it.”

“It won’t be forever. Just long enough to save the ponies we love,” Cadance responded, accepting a bit which clicked into place. “You’llth thee. Juth long enuth.”

“There will always be more ponies to save,” Luna countered, allowing her back hooves to be moved into place for their own hobbles. “Thou hast condemned us to the hooves of madmares. Madmares.”

“Immortal madmares,” smiled Starlight, as she bitted and then collared Luna, reducing her louder protests into a chorus of moos.

“Well done, Starlight,” Twilight praised, when she arrived minutes later. Cadance and Luna were already undergoing their introductory milkings, with Cadance clearly revelling in the experience as milk flowed out of her in a steady stream, easily outproducing the drips that came from the teats of the still protesting lunar alicorn.

“RE-MoooOOOO,” railed Luna fruitlessly, taking a powerful shock to her nethers for her troubles, which induced a short-lived burst of milk.

“Wow, I never would have thought Luna was into pain play,” Starlight commented with a smile, while Celestia hung her head forlornly, having already tested the shock power of her own restraints and having come out a second and decidedly submissive best to them.

“Sexual pleasure stimulates milk production due to hormones secreted during arousal and orgasm,” Twilight stated, checking on each of the members of her growing herd. “If pain in moderated doses gives Luna pleasure, than that’s exactly what she’ll get.”

“Nah! Nah!” decried Luna, shaking her head in the negative, until Twilight triggered the plugs still seated inside of her. “MOOOOOOOOOO.”

Milking didn’t take long, but Twilight took the time to make sure that each of her animals came at least once from their stimulation, no matter what form that stimulation took. Just because the ponies in her care would live lives of bondage from now on didn’t mean it had to be a life of suffering as well.

“Wow, a pint already Luna. Well done,” praised Twilight, once all three alicorns were allowed to rest from their efforts. Twilight had been so busy with the procedure that she failed to notice that there were decidedly more restraints in the room than there had been a few minutes ago.

“I’ve put a chart up on the wall so that we can keep track of the herd’s progress. Maybe you should enter today’s numbers?” Starlight suggested, making a few last minute preparations.

“That’s a wonderful idea Starlight! You can never have too much data,” Twilight agreed, turning to the chart with undisguised glee. “Let’s see now. Celestia is up to a full gallon a day now. Cadance is already at two pints, likely because she weaned Flurry Heart not too long ago, and Luna has a pint and a half. Huh, that’s odd.”

“What is?” Starlight asked.

“Why is my name on the ch—”

Twilight never felt the stun blast that hit her directly at the base of her brain, instantly rendering her unconscious. So it was with some surprise that the return of consciousness found her tightly strapped and bound in a harness and bridle of her own.

“What?” Twilight just had time to ask, before the well-timed movement of a bit pinned her tongue in place.

“I’m surprised you never carried your concept through to the logical conclusion Twilight,” Starlight was saying, as she fused yet another ensorcelled collar around the throat of the lavender alicorn, ensuring that it could never be removed. “If one alicorn giving milk is good, and two is better, then all four would maximize our production.”

“AHMoooooooooo,” came from Twilight Sparkle, as she jerked and pulled at her restraints. Restraints that were just as solid and secure as those holding Celestia.

“Tolth thee,” Luna managed to say, with a mirthless chuckle.

“Don’t you worry though Twilight, I’ll make sure you enjoy yourself for the rest of your very, very long life. Isn’t that right, Big Mac?” Starlight asked, and at the prompt the large red stallion stepped into the room.

“Eyup,” Big Mac said, and Twilight’s eyes went wide at the size of the erection the stallion was sporting.

“You’ve always had a thing for Twilight, haven’t you?” Starlight asked, and the pride of the Apple family slowly walked around Twilight like a timber wolf scenting a meal.

“Eyup,” Big Mac said, sliding his muzzle up along Twilight’s nethers, his tongue leaving a slick trail as it cleaved her inner lips and igniting a fire in Twilight’s loins.

“I’ve seen what you keep under your bed, Twilight,” Starlight commented, attaching the milker to Twilight’s teats and taking care to tighten the straps of her harness an extra notch. “All those magazines. ‘Big Earth Studs’, ‘Plowed Mares’, ‘Harnessed to Lust’. All those fantasies you never would admit to. Now you get to live them.”

“This ain’t gonna hurt her is it?” Mac asked, even as he reared up onto Twilight’s hindquarters. “And Granny is gonna live fer’ever?”

“Of course she will, and Twilight’s too important to risk hurting. All of them are. Besides, she wants this,” Starlight replied, turning on the machine, which began to suck and pull at Twilight's nipples; stoking Twilight’s arousal higher and the alicorn involuntarily pushed back against the huge shaft that was poised to plunder her inner walls. “See?”

“EYUP!” Big Mac declared, driving forward and penetrating the slick walls of the bound mare with surprising ease.

Twilight’s whinney at being filled to her core converted into an ecstatic bovine sound, and for several long minutes all that could be heard in the barn were the wet slaps of flesh on flesh, and the rhythmic beat of the milker as Twilight experienced for herself all the sensations that she had made her friend and mentor endure for several weeks now.

Sensations that just as surely drove her to orgasm even as they induced the flow of a tiny dribble of milk. Starlight Glimmer made a small notation on the chart before turning back to the scene of Big Mac rutting Twilight a second time.

“Now every pony will be equal. It’s just a matter of time.”

Author's Note

Sorry this one ran late. Literally finished it at the last second here. This chapter, is the dark ending, if you like things dark and scary. Any typos are my fault and not my editor's. In other words, I fucked up, not them.

One other chapter, likely sometime later, with a much happier turn of events.