If Iron Quill was the kind of general he’d copied stories about in the scrolls of ancient history, he probably would’ve flown proudly through the camp then, uniting the surviving companies and making some decisive orders that would save the army. Unfortunately for Nightmare Moon, unfortunately for their chances of freeing Equestria from the tyrant and getting their revenge, he wasn’t a legendary general.

Iron Quill flew straight back to the place he’d come from—the stockpile.

Despite the disaster he now knew they were in, despite his terror over their future, some small part of him filled with pride when he saw what had happened since he left. Silver Needle had been hard at work, along with every other member of his staff. The supply tent was back up, and the wooden walls of the granary were already rising once again. They had always been temporary buildings—soon they would be back.

“Sir!” Silver emerged from the tent, a quill and a scroll levitating in front of her. A checklist of some kind. She made it most of the way, then saw Penumbra beside him.

He landed. “Silver, this is Penumbra. The princess, er…”

“Knew we would be guano without me,” she supplied. Her voice was dark and smooth, a melody carried through each word. She also spoke far more than the stallion he had last seen.

“Yeah,” he admitted. “Fine. Report, Silver Needle.”

“Uh…” She whimpered. “I can’t give you the complete inventory, but… it looks like we have everything. We will require several shifts to know for sure. I can have the inventory ready in two days.”

“Two days.” He closed his eyes. “Silver Needle, congratulations. As of this moment, you are now Nightmare’s Chief Supply Officer. You’re a colonel.” He reached down, carefully removing the metal pin from his uniform and tossing it towards her. She caught it in her magic, speechless.

“And… what about you, Quill? Was she that upset with you? Nightmare would really… take your commission?”

He shook his head. If it weren’t for his new set of watchful eyes, he might’ve said something like “I wish.” The idea of losing his commission sounded a lot easier than somehow saving this army and everypony that was part of it. But there was no telling what a Voidseeker would do. He’d known them to kill for disloyalty, no matter how important a pony was. He could be taking no chances today.

To his surprise, Penumbra actually laughed from within her suit. His whole life, this sect of warriors had spoken to him so little, but now... “It would be easier for him if she had. Better to be a slave than the work our princess has in store for General Iron Quill, Lord Commander of the Lunar Army.”

The weight of that title settled on his shoulders like a mountain of shattered moon-rocks. He wavered, nearly fell over. Three days. He couldn’t give up.

“Penumbra,” he said, more directly. “I need to know what we have. I’m an inventory pony, it’s what I do. How do I marshal the surviving captains?”

Penumbra laughed again, though some of the bitterness was gone, along with the amusement. She seemed a little… annoyed? “You expect my help?”

“Why not?” He flicked one bat wing up towards the sky. “You breathe air too, don’t you? You eat food and drink water the same as us. Do you want to live through this or not?”

She had no sarcastic quips this time. Good. “There’s a call to assemble. Only the Lord Commander is permitted to blow it. You should have a horn here somewhere, don’t you?”

Right, stupid. He was so off-kilter by everything he’d completely forgotten about the call. Now that he was the Lord Commander, it was his signal to blow. “Silver, get me a horn from the stores.”

A few seconds later, it was in his hooves. He lifted it to his lips, closed his eyes, and let off four short blasts.

Having the entire inventory at his disposal meant he had the resources to erect a pavilion while he waited, filling the inside with an intact table and chairs for the ponies he expected. It shouldn’t take them long.

It took nearly an hour for the army to respond to his call. Each company should have been marshaling to arms, sending their high-officers forward to plan the next battle. But of course there was no battle up ahead. And it wasn’t often that the call came from the rear.

Still they came, beleaguered ponies trickling in. A few actually wore captains’ uniforms. Most of them wore lesser ranks, those who had survived to take their captains’ places. Twenty ponies in all, for the twenty companies. When at full strength, each would represent two hundred fighting creatures. Now… probably less.

“I don’t see Stalwart Shield,” said Permafrost, one of the few captains among the crowd Quill could see. He shuffled forward, looking around at them in disbelief. “I knew in my nightmares I’d have to take command of this sorry lot, you—”

Penumbra nudged Quill sharply in the flank, and he strode forward. Of course every captain knew him, mostly as the pony who stood between their ridiculous demands and the army running out of grain. But whatever they were about to say didn’t make it as far as the crown on his head.

“You,” Permafrost said. “By what right of the heavens above or sea beneath are you wearing that?”

“By appointment…” His voice turned into a batlike squeak, and he cleared his throat. “Nightmare Moon herself gave it to me,” he said. “And the responsibility of saving this army.”

“You?” asked another voice, all disbelief. “The monk? Shouldn’t you be counting rice?” More laughter.

“If I had time to count rice, I would,” he said, ignoring it. He might not know how to command an army, but he did know how to ignore a pony who was mocking him. “Our princess has told me we have three days until we all die.”

That silenced them. The less-senior ponies he saw visibly paled at the news, retreating a few steps. But there was nowhere for them to run to.

“Then why put anyone in charge?” asked Moonshadow. One of the only other surviving captains, one Quill didn’t completely hate. “Open the stores, let the stallions and mares enjoy themselves. If we’re dead anyway…”

“We will die if we do nothing,” he said. “I’ve been chosen to prevent that. There will be no final feasts burning off all our supplies. We will need them to survive up here, once we know how.”

“Survive what?” Permafrost asked. “We’re… I don’t know if you’ve looked around much, monk. There are no armies here. There aren’t even any trees. I have no doubt the princess is correct if she says we are in danger, but I can’t fight what I can’t see.”

“We’re in no state to fight,” a young unicorn said, adjusting his ill-fitting captain’s helmet. He barely looked out of basic training. “Half my company is gone, Lord Commander. We were at the front.”

“You don’t have to call him that—”

They did. He glanced to one side, but Penumbra only shrugged at him, unhelpfully. She wasn’t going to step in to reinforce his authority.

“Permafrost, I need you to keep order. Help the other companies make proper graves for the dead, and make camp.” He spoke quickly, directly. Didn’t even hesitate long enough that the captain could object. “Moonshadow, did your company’s alchemist survive? I want him here. And uh…”

He pointed to a third pony, an earth pony wearing the skull crest of Motherlode. “All your surviving scouts, Motherlode company. Send them here. Everypony else, keep good order in your camps, and do not tell them of the danger we are in. Expect an order to relocate to come any moment.”

Quill expected Permafrost to keep arguing, maybe to try and take the crown from his head. He strode up to Quill, wide bat wings spreading a little at his side. “When you realize you’re in over your head, Quill. You know where to find my camp.” Then he left.

Quill hadn’t called an end to the meeting, but apparently he didn’t have to. The others watched Permafrost leave and scattered themselves, even the greenhorn recruits standing in for their dead officers. Quill felt his shoulders slumping, under even more weight than the strange gravity of this place.

You’d think for all the time we swore on the beauty of the Moon that she would be a little more welcoming.

“I’ve seen worse,” Penumbra said, circling around him like a predator looking for the best half of meat to latch onto.

“You let them walk all over me,” he said, pushing away from his chair and not caring that it fell over sideways. “What did you expect to happen?”

“Wait.” She stopped dead, wing on his chest. “You thought I was supposed to help? To… give you authority or something?”

At his nod, she rolled her eyes. “I take it back, maybe I haven’t seen worse. You…” She hesitated. “Stars above, you really are that clueless.” She sat down on her haunches, reaching up and unwrapping the black cloth around her face. There was nopony else in the pavilion with them, no non-bats to look on her face.

She was even prettier than her voice had led him to believe. Though she wore the armor of battle with confidence and carried her enchanted blade with skill, she was still young. Young compared to a former monk like himself, anyway. “Iron Quill, look at me.”

He looked.

“If I had supported you now, maybe threatened them in Nightmare’s name… would that have helped?”

“Yes,” he answered reflexively. “Everypony knows how powerful you are. You’re her will, while she can’t be here. If she was here—”

“If you need my permission to be in charge, then I’m the Lord Commander, not you. It would only be a matter of time until one of them tried to argue that he or she should take your place. You would have ponies talking to me when they wanted things, asking my permission. They’d see you as an indulgence, a puppet. Is that what you want?”

He didn’t need to answer that.

“If you don’t want them to walk all over you, don’t let them,” she said. “They’re only captains. You’re the Lord Commander. Their lives are in your hooves. They’ll realize it sooner or later.”

“We don’t have later,” he said, walking past her, past the empty table to the pavilion’s wide entrance. There was a pony on their way towards them, struggling a little as he dragged a cart along the dusty ground.

Sylvan Shade, he realized. The alchemist. At least Moonshadow had followed his orders. Maybe Motherlode Company would send the scouts too. He gestured urgently to the pony as he approached, waving one hoof.

He watched as the pony rumbled up, his heavy wooden cart overflowing with crates and tightly-wrapped arcane bundles.

“I’m told I’ve been called for,” the pony said, as he got close. He dropped into a slight bow. “It’s a great honor to be requested by a pony with such a history as yourself. My name is—”

“Sylvan Shade,” Quill interrupted. “Inventor of Builders’ Lime, architect of Manehattan Harbor, intellect so great that Star Swirl himself feared your wisdom.” He rolled his eyes. “Am I missing anything?”

“Y-you’re uh…” He trailed off, visibly deflating. Quill’s recognition had stolen all his energy, replaced with simple confusion. “You forgot about my achievements in agriculture, growing wheat even in the desert.” Then he relaxed, and his tone changed. “Who are you?”

“Right now? I’m the Lord Commander of the Lunar Army, Iron Quill.” He stepped aside, opening the entrance. “Please, come inside. You’re the closest thing we have to a scholar, Celestia help us.”

He heard a hiss from further in the tent, and caught Penumbra glaring briefly at him. So maybe he wasn’t wrong about everything their religion taught.

“An army that needs a scholar,” Sylvan Shade said, standing a little straighter. “I knew my time would arrive. No doubt you’ve reconsidered my offer of a way to penetrate the castle walls without magic. Stalwart Shield rejected my wisdom, but…”

“We won’t be returning to the castle for some time to come,” Quill said. “But I might need your, uh… we can call it wisdom. Do you know where we are?”

Sylvan unhooked himself from the cart, and followed him a moment later. “Yes, uh… yes! I’m fairly certain our princess has moved us to the safest place for her, where her magic is strongest. We’re standing on the Moon, yes?”

He nodded. “How well do you understand the Moon?” He raised a wing, silencing him. “Besides holy, beautiful, sacred, greatest of the sky, softer and kinder than the sun… yes yes. All of that. But otherwise. What is known about her?”

“Well…” Sylvan took the offered seat at his table, when most of the captains hadn’t. “It is a place like Equestria, with its own geography. Its days last for twenty-nine of ours, followed by darkness. It regulates the tides. Many believe it is hollow, or made of various strange substances. Lunarium is the most popular theory, a silvery metal with profound strength and endurance to magic.”

“We don’t need new swords…” he said. Though if it were five years ago and this campaign were still a dream, I might’ve been eager to hear those stories. “Wait, hollow? What makes you say that?”

He shrugged. “I’m an alchemist, Lord Commander, not an astrologer. I can only tell you what has been told to me. Some of it may be true, or perhaps it is all wrong. I never imagined we would be able to travel here physically to test it. When we return, the entire world will shake from the discoveries I will make here.”

At least he didn’t get up to leave. “We… won’t be able to return,” he said. “At least not now. The princess said that the Moon has no air. She called it a… hard vacuum. Do you know what that is?”

He could see from Sylvan’s face that he did. His ears flattened, and he glanced over his shoulder in horror. “How are we still alive?”

“Princess Nightmare Moon holds the air at bay,” he said. “For the next… three days. Less a few hours now, I expect. Three days before her magic ends.”

“And we’re all…” He gulped.

“You knew the term,” Quill said, impressed. “I’ve… I’ve not studied as widely as you, I admit. I mostly managed affairs for the monastery that was my home. How did you know what the term meant?”

“My alchemy, obviously. Certain reactions cannot take place when air is present, and it must be kept back. Some materials transform when the pressure is reduced. Pressure is… the amount of air, usually in some closed vessel of glass. I have a reaction flask in my cart there, one I can use to create a small amount of vacuum. I have… seen what it can do to a mouse. For… entirely scientific reasons, of course.”

Quill shuddered at the thought, though he didn’t ask for details. At least now he got some idea about why Sylvan Shade might’ve ended up with the Rebellion. Perhaps he was a scientific extremist, as well as a braggart who had slept with one too many important mares.

“Suppose we needed to… construct such a vessel, large enough to house the entire camp and everypony who still lives. I don’t know the number, but… if we lost less than half in that siege, we should still have two thousand fighting ponies. Another three thousand in camp staff, followers, and…” He cleared his throat. “Helpers. How would we contain the air they all depend on?”

Sylvan’s horrified face did not relax. “You’re asking how to… contain the air that thousands of us are using to live? Stars above, Lord Commander, I don’t think you know what you’re asking.”

“I don’t know,” he said, without shyness. “So tell me. What am I asking?”

“Air might be invisible, but it has strength. This is why the pegasus can fly so well. A weak vessel that all the air is removed from will shatter. I have attempted to measure this strength, though my results would mean nothing to you. I assume if we wanted to construct something of the reverse, then we would have the same problem. I lost many shattered vessels before I found one strong enough to reuse.”

“Show me.”

Sylvan walked out, his eyes watching the sky as fearfully as a watchpony who knew there were enemy pegasi flying overhead.

As he worked, Penumbra circled past him, sounding annoyed. “Is this really the best you can do to save us? This… charlatan? He sounds like the greatest fool in the army.”

“Do you have a better idea?” he asked. She didn’t, returning to a dark corner of the tent to sulk.

Sylvan Shade returned after a few minutes of shuffling around, with a tightly packed bundle. He removed it, setting a heavy box and bellows and several thick pieces of glass on the conference table.

“Here is my strongest vessel,” he said, depositing the almost clear glass in front of Quill. The glass was curved at the bottom, without any sharp edges, and was as thick as his hoof in places. “This is what it would take, only… larger. Beyond even the greatest glassblowers in Equestria.”

“So it couldn’t be built,” he said. “Are there… any other materials that can hold back the strength within? Spells perhaps?”

Sylvan tapped his empty forehead with an exaggerated hoof. “I know as little of spells as you, Lord Commander. But our princess had demonstrated that there are indeed spells strong enough. But… if you allow me to be bold, I doubt that will be the answer. My entire company had two unicorns. How many does the whole army have?”

“Not enough,” he agreed, voice reluctant. “Buck it all. There must be a solution. I refuse to believe we’re doomed to die.”

“I hope you’re correct… as much as you do, Lord Commander,” Sylvan said. “But one thing I cannot provide you is a magical solution to this difficulty. There are no spells that prevent a pony from needing air. The suffering I’ve… observed under these conditions… will strike us down as well as any rodent, I can promise you that.”

Quill turned over the pressure vessel in his hooves, staring down at its rounded interior. He looked up and out of the tent, where Equus was still high in the sky. A little ball of light, where life was possible. Instead of the gray wasteland around them.

“So a container would have to be… this thick at least to hold air, yes?”

The alchemist nodded.

“And the moon is hollow. Surely to exist for so many thousands of years, it must be strong. Thick enough that we could fill it with air, perhaps?”

“That is…” Sylvan opened his mouth, then shut it again. He looked outside, then back at the container. “Positively insane, Lord Commander. And if I have learned nothing about the most brilliant ideas, it is that they always are.”

“Perfect.” Outside, he could see three ponies in scouts’ green, landing in the sand beyond the pavilion. Motherlode had sent them after all.