Pathfinder took a slow, exaggerated breath. Of course it no longer served the same purpose, since they didn't require respiration. That cavity worked only to allow them to speak. Which was what Pathfinder did. "You are going to tell me... what you did to me," he said. "And how we reverse it."
Bit didn't look away, even as he advanced on her. Though maybe she shouldn't expect entirely rational behavior—he had only just been created. In some ways, he was also the first of his kind. A pony of crystal created from something organic, instead of computers and memories. She walked over to the nearby console, and pressed a few keys to begin the recording. She would worry about classifying the files later, when she didn't have a potentially dangerous pony in front of her.
"I saved your life," Bit said matter-of-factly. "You were dying, Pathfinder. I did what you suggested, trying to keep you alive as long as possible for the earth pony magic to work. By the end, you slipped into an unresponsive coma. Look." She urged him to the now-dark medical console, bringing up the recordings of the last week. "This is just before treatment. You had suffered a total failure of the upper and lower GI, with infections spreading through your lymphatic system. Necrosis of the soft tissue was advancing rapidly. If that damage reached your brain, treatment would be impossible. I couldn't wait another moment."
He stared up at the screen, which showed a stylized cutout of his body, with several glowing red patches. Of course he showed no signs of recognition. He didn't know what he was seeing.
"You told me to save your life," she continued. "I had hoped to explain what the procedure would do to you. But I didn't know if I would succeed until the end. I did not want to promise you success until I knew we had achieved it."
Pathfinder lifted one of his legs up to the light, looking through it. She'd seen that face before, on more than her fair share of ponies. But Crimson had worn it last, when he looked out at the mob. "What did you do to me?" he repeated. "And how do we reverse it?"
Bit circled around him, removing the crystal-scanner from the desk. The simple ultrasonic probe would do far more for him now than any of the medical equipment in the tower. She touched it to his back, moving it slowly along the center mass and checking for cracks. She did not remember her own birth, but some record she found suggested it was far more difficult than this. Creating a pony without a living base was far harder, just as the wizard had thought.
You were right. Once she'd taken the diagnostics, she would have to change the status of this project in his files. Even if the Wizard never came back, the computer had to be kept in order. It deserved to mark his success. "I had no medicine, and it was too late to make the drugs that would save your body. So I pivoted to saving your mind.
"You are a... I'm not sure what we're called. A pony made of crystal, now. You should have all the same memories, the same personality, but none of the biological needs. Our bodies require only the background magic radiated by the Zircon, or any other magical source. You won't get cold, you don't need to sleep, or worry about the radiation that killed you within the palace. I am... unsure what other ancient defenses will make of you. But probably those will read you as an automaton, and ignore you unless you are doing active harm."
"An automaton," he said. "That's the word you used for the death machines. But I don't feel like I want to kill ponies, or protect an evil king." He took a few tentative steps forward, scanning the room. Then he darted for the restroom, crystal hooves clattering with every step.
Bit followed close behind, tossing the scanner back onto the desk. "You won't need that anymore, Pathfinder! Your body will only produce waste when you're drinking a repair solution to recrystalize internal damage. I don't detect any cracks—"
He wasn't going to use the facilities. Pathfinder stopped in front of the mirror. He touched up against the glass with a hoof, twisting to one side, then the other. Bit stopped in the doorway, lowering her voice to something calmer and more respectful. "Those bumps and crystal protrusions aren't normal, they're part of the growth and repair process. A few hours in the polishing tank will take care of all of that. It won't itch after that. Unless you break, and we have to repair something. But you should probably try not to let that happen."
"Polishing tank." Pathfinder turned, ears still folded, eyes wide. "Can you go back? Now that I'm safe from radiation, how do we make me normal again?"
Even Bit's limited predictive ability required very little exercise to realize that her next few words would probably be hard on him. But he would have to confront the reality sooner or later. "That is not possible. Your mind was converted to a holographic, distributed crystal matrix. You're effectively a damage-resistant, error tolerant computer. The Wizard knew no way to reverse it. But why would you want to?"
Bit had no experience for what to do with a pony in such distress—only memories of what the Wizard had tried to do for her. She wrapped one arm around his shoulder. Apparently that was the right thing to do, because he didn't force her away. "It might be disorienting at first, Pathfinder... but this state is ideal. You don't age anymore. You can't get sick. You never have to eat or drink, unless you want to. Wishing to reverse this process is not a rational desire."
He was silent for a long time. Like her, Pathfinder was completely still while he thought. There were no subtle adjustments for balance, no twitches or gentle swaying to his breath. Pathfinder was as still as the crystal that made him, as only the two of them could manage. "I don't know... how I feel about this. But I wanted to live no matter what. I followed you... you said not to come, and I went anyway. Sooner or later the consequences were going to catch up with me."
He ducked out from under her leg, turning back to the tower. "You said there's a way to deal with this awful itching? Let's do that. I can barely even think straight. Just don't call it a 'polishing tank' again. I'm not a noble's necklace." He sighed. "If there's no changing back, maybe I should be looking into how to fake it. Maybe there's some... cream we could use, to make it look like we have fur."
She didn't argue the absurdity of that suggestion. Not that it was impossible, of course—magic could do almost anything with the right application of leverage and resources. But wanting to appear like he was still constrained by biology, more than just avoiding the fear of a nervous mob—that she couldn't understand.
She led him down to the polishing tank, careful never to call it by its proper name. The box was entirely dark inside, with a thin metal harness to keep the pony securely in place. A thin layer of grit collected near the drain at the bottom, though that was all.
"You climb in this?" he asked, resting one hoof inside. "The evil king had more spacious prisons."
"Rarely," she answered, slipping past him to open the harnesses. They didn't lock, since of course there was no automaton that required polishing against its will. This might be the only polisher built in pony shape in all of Zircon. "You only need polish when a fresh crystal grows. After today, that won't happen again unless you crack. I suggest avoiding that with all possible caution—suggestions that we cannot experience pain because we aren't biological is not true. Cracks are incredibly painful, and do not heal naturally. Fortunately, repairing them is easy enough. I've been fixing my own damage for centuries now."
Pathfinder sighed, climbing in beside her. "Show me what to do, I guess."
She clicked the harness into place around him. For such a large earth pony, it almost didn't fit, though thankfully he was just small enough. Finally she stepped back, resting one hoof on the controls. "It won't hurt. I don't have any comparisons for what it feels like. Given how much debris you're carrying, it should be a relief. Just don't try to leave until the cycle is complete. The machine will open automatically. But if you break it, we don't have another. I'm not sure how long it would take me to repair."
He nodded, slumping down against the restraints. "Got it. Stay here. How long will this take?"
She shrugged. "The standard maintenance cycle is two hours. But you need considerably more polishing than that. Not more than a day."
"You expect me to sit still in a black box getting blasted by sand for... a day?"
She nodded. "You won't have to repeat the process again. But the crystal grew roughly over your necrotic flesh—the computer will need some time to make your body even."
"Ponies don't work that way," he said. "Doing the same thing all day—that's how you make someone go insane. Forgetting how impossible it is. I can't stand up all day. What am I supposed to eat, sand?"
Her ears twitched in frustration. Had he even been listening? "You don't have to eat anything, Pathfinder. And yes, you can stand up all day. I've been standing since the moment I was created. I promise it isn't as hard as you think. And you won't go insane, you'll see. The Wizard was smarter than all that. He was designing a species to last—he knew you were going to live much longer than organic ponies. I don't understand all the changes, but I know what I've experienced.
"We don't see time the same way. Other ponies need constant stimulation, we don't. If you aren't thinking, you'll... drift. Your body can maintain autonomous functions without conscious input. It's relaxing, soothing even. Cleaning windows, fixing machines... you'll see. I know you don't think so now, but this is an advantage. You're growing into something more than you were, not less."
He didn't reply, just continued to hang there in the restraints. Bit could've tried to convince him a little more—but all that itching probably was making him insane. If he started scratching, he might cause hairline cracks that would eventually spread into real ones. She activated the machine, instructing it to prepare a new automaton for service. The screen reported what she already knew—that there was considerable pitting and structurally unsound crystal throughout his body.
It took the old machine a few minutes humming away to finally come up with a repair plan she liked. It would actually take two days to complete, trimming away enough material that Pathfinder would come out smaller than before. But he'd been so huge already he had a little growing to spare. At least this way he'd look natural.
"Isn't it going to do something?" he called from inside. "I don't feel anything!"
I probably should tell him how much this machine is going to do. This was different from accepting treatment—if she didn't repair him, he wouldn't just look strange. All that weak crystal would present a structural hazard. It might even be enough to shatter him. "It was just preparing!" she yelled, pressing the activation button. "I'll see you when it finishes! Don't try to open the machine until it's done!" Fans spooled to life, water-pumps hummed, and whatever he might've said was drowned in the sound of sand on glass.