A heavy steel door slid aside on recently-oiled rails before Shinespark's cloud of telekinesis, forming a sharp contrast of retrofitted technology against the ancient bricks and peeling paint that made up the rest of the building. Cold air blew against Starlight's face as it rolled open, a draft entering through some unseen orifice that didn't also permit light.
She stepped forward in Shinespark's wake, the armored unicorn's hornlight reflecting cleanly off puddles on the concrete, appearing as a blue sphere against the cavernous darkness. The warehouse's central chamber stretched endlessly before and above her, faint gray light making its way in through cracks that might have been grimy windows in and near the ceiling and not extending to the floor. They revealed the curved silhouette of something massive high above her, and she walked with her head tilted skyward, trying to make it out.
"Careful!" A metal limb shot out, halting her in her path, and she realized Shinespark had veered to the left. "This used to be a dry dock," Shinespark explained. "There's a pit in the center of the room where ships once went. If you fall in, I can catch you before you hit the ground, but it won't be pleasant. Watch your hooves, and stick to the left."
Rattled, Starlight stared at the ground, falling firmly into step behind Maple and Shinespark. She tried again to make out what was around her, but it was like the room's darkness didn't want to be parted by her guide's horn... or Shinespark wasn't even trying.
"Could you turn your horn up a little?" Maple asked, apparently mirroring her thoughts. "I can barely see in here, and if there are hazards we need to be avoiding..."
"Just a second," Shinespark replied, taking a smooth right turn. "I just... want to get us in the best angle to see this before I make it obvious."
Starlight coughed. "Sure! I'm not tired! Just make us wait even longer, because I'm not cold and I don't have a headache and it wouldn't at all be fine to just tell us what it is! Come on..."
Ahead, she saw Shinespark's ears fold, but the mare kept walking... for what could generously be called ten seconds. "Here's good," she decided, coming to a halt. Her horn pulsed slightly brighter, and from the distance came the sound of a switch being thrown to telekinesis. High up along the walls, in the four corners of the room, powerful floodlights ignited, bathing everything in harsh white light.
The lamp beams shone across the cracked, buckled floor, hiding the puddles with their glare and revealing every fault and defect left in the building from age. Wall support beams, made of thousands of strips of metal bolted together in reinforced patterns, stood at minuscule angles, dented and caked in rust. Crates of material and abandoned tools sat in covered areas around the edges of the room, and several more doors and exits were visible, scattered around the perimeter and broader than they were tall.
The hole Shinespark described was readily apparent, a sheer vertical drop as if someone had carved a rectangle out of the concrete floor with a laser-guided knife. It dropped into a deep, metal-lined trench, the walls stained with rust in a clear indication of where the waterline used to sit. At the bottom, a muddy once-riverbed held half an inch of water, hammers and other supplies still poking above the surface. The ship bay was even complete with a sizable wooden boat hull, held in place by sturdy-looking supports with a cabin and railing visible above, though it was missing obvious features Starlight associated with big boats in Equestria like a mast, sails or rigging.
She blinked again at the boat. If it had been left there when the water drained, why did it have supports? And why was there a lowered boarding ramp on one side?
"Here she is," Shinespark breathed proudly. "This is what we've been working on. Do you like her?"
"A boat?" Maple's brow furrowed. "But there's no water! And-"
"It's an airship," Starlight realized, eyes widening. "That's why you cared so much about being able to put pegasus flight magic in a machine!"
Maple frowned, expression split. "But it looks nothing like the airships from the Sky District! It looks like a frigate, or a sea vessel from old picture books..."
"I don't know if you ever learned this, or remember," Shinespark said, floating up next to the wooden hull and tapping it with a hoof, "but the original specification of Project Aslan was to make a ship that could sail the sky and the sea."
Maple sat down, eyes wide. "Project Aslan? But... that was cancelled twenty years ago! It was..." She paused, letting out a slow breath. "You never stopped working on it, did you? You let Mobius think you had, but you hadn't. This is it. You're making another airship..."
"Not quite 'never stopped.'" Shinespark landed and shook her head. "When the project was first suspended after the Spirit crashed, its state was in limbo for most of a year. Eventually, after Arambai conceded to Mobius to try to bring Sosa back together, Mobius wanted to permanently shut it down... and Arambai publicly agreed with him. But he protected copies of all the engineering and design documents related to it, and hid them away. For the next ten years before airships became a world reality, he had his engineers work on them under his own resources, though those weren't vast and he neither made nor expected to make much progress. It was more a statement of defiance than anything. Eventually, the papers completely lost their value as other nations and inventors copied or rediscovered many of the innovations that made Project Aslan special."
"But you restarted seven years ago," Starlight said, standing by Maple's side.
"Ten years ago," Shinespark corrected. "There was a three-year period in Ironridge's history when it was obvious commercial air travel was becoming a reality, but before Sosa officially surrendered, where Mobius had been proven wrong about what would happen and Sosa willingly gave Arambai complete control of the district. He knew Sosa's situation was hopeless, but decided the impossible chance of reviving this project and making up those ten lost years would be better than completely giving up. There wasn't any chance of success, but it would at least give hope to the ponies working on it. The main issue was that simply making a quality airship wouldn't be enough with the present state of the world's technology - we could try to fix the issues with the original design, but it had been outpaced, and was no longer revolutionary. Nobody had copied our idea of a sea-sky hybrid, but that was it. We needed something that would do to air travel as air travel had done to water travel... and he didn't even know what that would be. But still, he tried."
She began pacing towards the boarding ramp, beckoning for Maple and Starlight to follow. "Three years in, he had nothing. Studying obsidian hadn't even crossed his mind. I knew about the project, but wasn't involved with it. But he had been making progress on the parts he already knew about: how to make a seaworthy ship. Doing something special with the air was a dream, but he put his time toward forging the best hull Sosa had ever built..."
Her hoof glided past the carefully-fitted wooden construction. "The outer wooden shell, in addition to physical and structural sealants and protections, is enchanted with the same mechanism used for protecting the skyport's roof: as long as it receives power, it can't burn, can't freeze, self-repairs cracks so long as all the pieces are present, and resists deformation from both point strikes and distributed force like wind and currents. Beneath that are multiple layers of a new alloy Mobius had been prototyping for ships over the past decade, but never had the chance to deploy."
"And then you got your cutie mark," Starlight filled in, predicting. "And that's the way you found to make the new ship special. So Arambai left because he thought it would really work, and you started making this for real."
"Pretty much!" Shinespark beamed down at her. "When that happened, we essentially had the hull complete... and that's all we needed the conventional Sosan equipment for. The rest, we could build in secret. So we towed it to this warehouse when we were moving all the other ships here to beach, and nobody noticed anything about it. Then he left, and now thanks to his research... It hasn't quite been a one-mare project, since I've had most of my ponies unknowingly working on components to benefit it, and some of the most trustworthy are even in on the goal. But this is what we're making. What will make the new Project Aslan better than every other airship anyone could make is that it's powered by harmony, instead of mana... giving it a theoretically infinite flight range. This is a ship that could cross the mountains and reach the Plains of Harmony."
"And how close is it to being done?" Maple asked, stopping at the base of the boarding ramp.
"Well..." Shinespark bit her lip. "We're always making adjustments and fine-tuning, as well as making her prettier... but she's essentially done. The only two things we need are a name and a power source. The former, we're waiting on the maiden voyage for, and the latter... has been problematic. My brand is more than two orders of magnitude too weak. We've been researching, but unless we can find a way to stabilize using multiple brands in series, we need something far stronger..."
Starlight's eyes widened. "You're talking about me, aren't you? Because I'm from Equestria? That's why you're so interested in me and keeping us safe!"
"From the Plains of Harmony?" Shinespark nodded. "I didn't want to make it sound creepy, but... yes. You produced some incredibly interesting test results in Arambai's lab in Riverfall, enough to suggest everything we know about how brands and more importantly ponies work is different there than it is here. I'm not talking about hooking you up like a battery to make this ship go, or anything. But if you'll let us, it would mean the world to us if we could study you to see what you have to teach about the workings of harmony." She winked. "And as a bonus, there's a very good chance we'd learn how to fix your horn."
"Can I..." Starlight swallowed. "Think about it?"
"Of course." Shinespark bowed as low as she could. "I know you have a lot of reasons not to trust Ironridge right now, and I'm sorry about that. You're special, Starlight, and I don't think I can emphasize hard enough that we'd make sure you knew everything that was going on and only did what you let us."
Starlight gritted her teeth, suppressing an old itch at being called special.
"In the meantime...!" Shinespark brightened. "Would you like a tour of the ship? We've got a ton of stuff here... including some very nice beds, if you're looking for a place to spend the night that doesn't involve concrete or that storm outside."
"Now that sounds like something I'd appreciate," Maple announced, perking up and stepping onto the boarding ramp.