Pieces

Wheat toast and strawberry preserves sufficed for breakfast the next day. Rainbow was gone before Celestia's sun had peaked over the horizon, a cry of "stunt practice waits for nopony!" still lingering in the halls behind her.

Twilight took to the town not long after, crude survey maps and notes almost overflowing her saddlebags.

Town hall for permits
Hardware store for additional safety equipment
Local construction union to look for day laborers
Note: Crew boss says I need to get here a lot earlier.
Post office to send a missive to the Sisters
Note: write the letter ahead of time instead of holding up the line
Town library to check out historical material (see attached list)
To File: Expand personal library. See new sublist "B"
Set appointment with county surveyor
Lunchtime

The hayburger sat half-eaten on the table, the fries cold. Her regular comfort food wasn't sitting well, despite hunger from the flurry of morning activity.

She kept thinking about the catacombs. About the unidentified noises and ancient corpses. About the bizarre plumbing running straight through the ancient skull. How the vector of the pipe seemed to point straight toward Ponyville. Something about the pipe itself that just seemed wrong but she couldn't put a hoof on it.

The quiet knot of terror buried under long years.

She pushed it back down and forced herself to take another bite of the hayburger before standing up and leaving the appropriate amount of bits on the table. Halfheartedly she marked Lunchtime off her list. Then, saddlebags laden with even more paper than she'd had a few hours ago, she headed back toward home.

"No doubt about it," she said, tapping on the line extending across the map. "If that pipe doesn't deviate, it leads directly to Ponyville. Maybe even directly to my castle here."

"It could be a supplementary water line from the Westfoal treatment facility," the county surveyor suggested. "A lot of stuff like that only gets put in one set of records because a construction crew is lazy with their redlines, or a permit falls through the cracks."

Twilight's eye twitched and she took a calming breath through her nose. "Okay, so I'll need to go over to Westfoal and request their records as well. But I don't think it's a water line."

"Why not?"

"I couldn't hear any water running, it wasn't insulated, and it was too small to be anything but… I don't know, a sink line or something." she paused. "Also, I… think I heard something solid moving, very fast. The pipe vibrated as it passed through."

Azimuth Reference ("please, just call me Azy") pursed his lips and stared at the maps thoughtfully. "From that it almost sounds like a pneumatic messenger tube, but it can't be that either. Too small." He paused, then leaned over the map and traced the dotted line of the pipe again. "Princess, who installed your plumbing?"

Twilight opened her mouth to reply, then closed it, then opened again, wordlessly. "I… I don't know. It was just… here."

He nodded. "I figured as much. Your castle has been a source of much, uh… consternation in construction and surveying circles. Considering, you know, it just…"

"Grew itself out of the ground from a magical crystal tree hidden deep in a forgotten cave?"

"Yeah that." He rubbed the back of his neck. "Nopony even knows how or why but it just seems to have made things just work for it. There's a new water line from the town main, installed to code and everything, but completely unmarked, unbranded, no tool marks, no fittings, no deviations to account for bedrock or aquifers or root systems, just… perfectly integrated to the existing water system and local geography."

He leaned forward for emphasis and scoffed in long-suffering disbelief. "Your castle didn't even impact the water supply, because the flow mitigation interconnects and backup pressure systems just somehow had an extra 1% safety factor beyond what was designed on the original plans. We measured it ten times!"

Twilight sat in shock. "Why was I never told about this?"

Azy threw his hooves in the air and half-laughed maniacally. "Because it wasn't a problem and nopony wanted to bother you! It's just weird!" He slumped back and sighed. "Given all that, I can believe without a shred of skepticism that there's a magically-grown pipe from here to somewhere, doing something, and it just happens to have passed through some undiscovered ancient tomb that you just randomly fell into yesterday."

"Catacomb," Twilight corrected absently. "Tombs are usually a sealed chamber, not part of a tunnel system."

"Whatev— I mean, yeah, of course, thank you, your highness, sorry."

Twilight waved off the platitudes. "Anyway. What can we do from here?"

"Um…" Azy thought for a moment, and his eyes lit up. "If you know where your sump is, we can try and find where the pipe enters the foundation, maybe. No survey crews have ever mapped out what exactly is going on under your castle, Princess. I'd be honored to have a first look."

"Not quite the first," Twilight said, standing and motioning toward a side door. "I had a plumber in here a few years ago to check some knocking pipes. He turned off the main valve and drained the system overnight, and he didn't mention anything weird about the setup."

"Find any leaks?" Azy followed her into the hall toward the basement staircase.

"That was the strange thing;" She brushed off the sudden chill that went up her spine. "No leaks. But the knocking never came back after… after that."

Azy nodded. "No news is good news, I guess."

Their hooves echoed on the hardwood panels inlaid to the crystal staircase with supernatural precision. Even the basement was intricately beautiful, though most of it was hidden under piles of messy lab equipment, past experiments, and endless scrolls of readouts and notes still waiting to be collated and filed.

Being a princess sometimes left precious little time for anything else, Twilight mused.

"Here," she said, opening an access door to the main water valve.

Azy frowned and looked around the closet. "No, this isn't right. There should be like, a cistern around here that collects ground water running under the building and pumps it out so you don't sink."

Twilight shrugged. "I have no idea where that might be."

"Hmm." He followed the pipe with his eyes, tracing backwards through valves and junctions to where a larger one came up through the floor. He leaned down and pulled a light gem out of his satchel bag with his teeth, shining it downward along the pipe. "If we could get under the floor here," he said out the side of his mouth, "that would help."

Twilight stepped forward. With a burst of magical energy, she sliced a thick section of crystal out of the floor and lifted it behind them. They looked down, into a maze of pipes and conduits, at a small clearance just large enough for an average-sized pony to walk through.

"Sisters-blasted son of a rutting mule—"

Twilight cut herself off and took a deep breath, exhaling slowly. One hoof at a time, she stepped out from the tangle of flex conduit, untangled her mane from the valve stem behind her head, ducked her head under the support beam, folded one wing backward, stretched the other forward and shimmied slowly into the next space.

Since her ascension she was, definitively, no longer an average-sized pony.

Azy was courteous enough not to say anything, making a show of inspecting the next bundle of pipe. "No steel here," he said. "I think this is some kind of heat pump."

"Fascinating," Twilight seethed. "Still no sump?"

"Well…" Azy cast the light gem around. Shadows played from the maze of pipes. The path behind them had fallen into shadow. Only a faint colorful glow from the thick crystal floor above indicated they hadn't left the boundary of the castle walls. "I thought this was the sump, but…" he tapped his hoof. It knocked hollow on the concrete. "I think this is just the sub-basement."

"Lovely." She rubbed her horn, which thankfully didn't feel cracked from the last three times she'd bumped her head. It was longer now, and she still hadn't gotten used to it. "Look away."

Without waiting, she rose up as high as she could and summoned a spell near the ceiling. Searing cold light diffused and bounced through the maze of metal, stone, and crystal. "Can you see anything from here?"

"Got it!" Azy dropped to his belly and shimmied under the nearest bundle of pipes. "That trapdoor. Pump is just past it. I think…" He sat up and glanced around. "To your left, five paces forward. I think you can get here through that gap."

"Thanks," Twilight replied under her breath with sarcastic enthusiasm. "Just what every mare loves to hear." She dimmed the light spell to a more manageable level and followed Azy's directions, tucking her wings and slouching her shoulders to squeeze through.

Moments later, the trapdoor appeared under her hooves. closed with a simple rotating latch. A thick iron pipe descended cleanly through the floor next to it.

With a burst of magic, she twisted the latch and lifted the trapdoor.

The heady smell of stagnant water rose into her nostrils and she coughed. Stepping around the hatch she peered inside with her light spell. There was no ladder, just a large void, partially filled with sickly moss, spiderwebs, and murky gray water of indeterminate depth.

"Azy, I found it," she called. Briefly she wondered how she'd gotten here before him. "What am I looking for?"

She leaned toward the hatch and angled her head to see further into the void space. It was huge, and broken up by vertical concrete columns that receded into the darkness. On one angle she could see a foundation wall, with a dozen pipes coming through it horizontally and angling out to various parts of the floor.

One of them was bright steel, barely the diameter of her horn, running along the foundation wall into the distance.

"Gotcha!" she exclaimed, standing up from the trapdoor. "Azy!"

Silence.

Twilight glanced around. Her light spell, bright as it was, cast more shadows than it dispersed. With a thought, she canceled the spell, plunging the space into darkness.

She couldn't see his light gem.

"Azy?" she called again, turning slowly. Her ears twitched, listening for a reply. "Where'd you go?"

Then she realized what was wrong.

The sub-basement had been filled with the gentle hum and pulse of equipment. Some magical, some mechanical, circulating and regulating the rhythms of her castle with modern conveniences.

She couldn't hear any of it now.

Her heart quickened and she recast her light spell. "Azimuth Reference!" she shouted, turning on the spot. "I am your Princess and you will answer me! Azimuth—"

Her rear right hoof stepped into empty space, and she fell backwards. Reflexively she twisted to try and catch herself, just in time to see a pipe coming up to meet her face.

She wasn't sure how long it was before she came to. The first thing she felt was the floor moving under her, concrete scraping her flank. She felt a pipe move past her, cool metal brushing against her leg. Something pinched at her stomach, a sharp pain moving forward up her belly.

It took another moment for her to realize there was nothing under her back hooves, just something pulling on her legs, dragging. Her bottom rib popped over the edge of the trapdoor as the world under her haunches disappeared.

"PRINCESS!"

A pair of forelegs wrapped around her shoulders and heaved. But the force pulling her hips into the void was stronger.

"PRINCESS, WAKE UP!"

The voice finally cut through the foggy pain, and Twilight's eyes snapped open. She gasped, wrapped her own forelegs around his trunk, and kicked as hard as she could.

The pull on her lower half released.

Azy groaned through gritted teeth with effort, hauling her up. She held onto him for dear life, swimming her back legs until one hoof found purchase on a pipe bracket. Pushing upward, her hips finally cleared the edge of the trapdoor, and she flopped gracelessly onto the concrete.

"Princess! Princess, are you okay!?" Azy gasped, chest and flanks heaving with effort, drenched in sweat. "We've got to get you out of here. Can you walk?"

"I… I think so." Twilight blinked at him through blurry eyes, only barely able to see his face in the dim light of the dropped gem.

He looked terrified.

With monumental effort, she struggled to her hooves and Azy supported her with one shoulder. Each step felt like a marathon. Every few lengths, he would scout their next path through the pipes, making sure there was enough room while Twilight leaned against a bundle of equipment.

Finally, they reached the cutout section of crystal flooring. Two shoulders above them the cool, bright light of the basement lab looked like freedom, simultaneously within reach and yet still a mile away.

"What now?" Azy said, panting. His forelegs were trembling and sweat beaded his forehead and snout.

Twilight stared at the gap. It would have to be close enough. She wrapped one wing around Azy's shoulders and took a deep breath. "Hang on."

She blinked, and purple magic popped like a bubble around them.

It wasn't a clean teleport; groggy and unable to make a precise calculation without line-of-sight, she decided that shoulder height above the floor would be a better choice than ending up partially inside it.

Still, it hurt more than she'd expected. At least she hadn't landed on top of Azy.

The poor surveyor spent the next several minutes curled in a ball as the adrenaline dump faded. He hugged his knees, mumbling over and over "I almost killed the princess… I almost killed the princess…"

Twilight focused on her breathing, touching one hoof to her chest on the inhale, and sending it toward the ceiling on the exhale. The pain gradually turned from sharp agony into a dull ache, even as her brain sharpened and the world stopped spinning.

Finally she stood up. Her knees wobbled a little.

"Princess, you're bleeding."

She glanced down. Dull red oozed from several lacerations on her stomach, hip, and back legs. None of them were particularly serious, but in aggregate it looked like a murder.

"I'll be fine," she said, pushing down the woozyness in her chest. "I saw… I saw the pipe, under the subfloor in the cistern. I couldn't see where it went…" Then she looked at his wide eyes. "Where were you?"

He gulped and broke her gaze. "I was right there," he said, "just on the other side of the pipes. I knew it was possible the pipes came in under the foundation, so I started the sump pump."

When she didn't reply, he looked back up. In a moment she could see it was shame in his eyes, not deceit.

"I heard you calling, and I came as fast as I could. I saw you hit your head, but I was still under the pipes, and I…"

She held his gaze for a moment longer, then nodded. "I believe you," she said, forcing her voice to be steady. Royal. "What happened was an accident. It wasn't your fault."

Azy gulped. "Um… I think I want to table this for now," he said, getting to his hooves. "I need to go home. Do you… Will you…?"

"I'll contact my friends," Twilight replied, voice more soothing than she felt. "Go home. This can wait."

She didn't call her friends.

With Azimuth Reference on his way home, Twilight drew a bath. Easing herself into the hot water was agony. Washing her wounds was even worse. Several times she had to stop and just breathe through the pain so she wouldn't faint.

Thankfully most were minor. Scrapes and cuts from sliding across the floor and metal doorframe.

From being dragged.

She pushed the thought away, but the sensation of something grabbing her legs lingered.

"You just tripped," she said to herself through gritted teeth. "You stepped into the hole, hit your head, and gravity did the rest. That's it."

Where was Azimuth? Why didn't he call out? Why was everything so quiet? Why—

"Stop," she said, squeezing her skull between her forehooves until it ached. "Just … stop."

The thoughts stopped.

By the time she'd drained the first bath, drawn a second, and washed the residual dirt and blood out of her coat, the sun was touching the mountains. Faint orange light suffused down the hallway as she shuffled to her room.

With a groan, she dragged herself onto the bed, not even bothering to turn down the covers or close the curtains against the late afternoon sunset. In moments, her eyes drooped, and she fell into an uneasy rest.