Starlight stared around the entry chamber to the Blueleaf generator, eyes reflecting countless sheens of bronze and silver. The place was harshly lit from below, sharp blue light stabbing up through the grated floor and casting their shadows against the domed ceiling. Pipes and valves covered the walls, obtrusions that made the room feel much smaller than it really was.
"Sure is bright in here for a place without power..." Maple mumbled nervously, standing close by Starlight's side.
Valey shrugged. "As long as we can get below the light, I'm good. More light means more shadows cast. Should we go down, or what?"
There was a staircase at the back of the room, hugging the wall in a spiral as it descended beneath the floor. Starlight's hoofsteps were slow and safe as she climbed; it was obviously intended for grown stallions and she was strongly tempted to take it one step at a time. Dangles of wires passed to their open side, and at one point a rotating belt moved by, the shaft humming with the rattles of machinery.
After three full revolutions, they reached the source of the light. Seated upon an iron pedestal and suspended in a mesh cage, a massive crystal floated, nearly steaming with energy. The edge of the room was lined with spiked apparatuses all pointed to the core, and below the floor a twisting trunk of cables descended even lower into the depths. Their staircase passed along the outside of the chamber, running behind the ring of devices.
"What is that?" Maple asked, eyes huge. Starlight leaned forward, curious as well.
"I dunno." Valey scratched her chin. "Like I said, I'm not a scientist. As best as I understand it, mana comes from the ground, or something, so maybe this is like a pump or reservoir? Beats me why it's glowing, though. Usually that's a sign that something's turned on and going just fine."
To the side, Redshift was pouting. "If you don't know what you're doing, why are you in here? I told you to open the door and let the Spirit handle it! Now you'll either break it harder on purpose, or they'll follow us in here and it'll break when they fight you!"
"Fat chance." Valey smugly turned away, cheeks puffed from the weight of her smile. "I locked the door behind us when we came in, just so that wouldn't happen. Besides, the inside of a giant machine feels like a pretty sketchy arena, anyway." Her eyes glinted in the blue manalight. "Sure would be cool, though. So many moving parts to use as platforms..." She blinked and shook her head. "Wait, I said I was gonna take Braen down without landing a blow, didn't I? Ah, bananas. Me and my big mouth. No epic machine fights for us, I guess..." She sighed sadly and looked on. "So these stairs keep going."
Redshift merely glared. "So you're just here out of cowardice, then? Is that it?"
"Okay, hold up." Valey spun, sat down on the landing, and bored her gaze into Redshift. "Maybe you missed all the spooky theorizing we were doing up top by the door, but I think there's something other here than a busted power plant and I wanna know what it is. Odds are you should too, 'cause it's probably the reason why nobody's coming to fix your lights. We are here to snoop around and stick our noses where they don't belong... which is totally where mine belongs, by the way, and that's good for me and you and everyone. That's why we're here. Do you want to hear what I said again?"
Unhappy at being called out, Redshift scowled, but said nothing. Valey frowned, flexed one wing... and grinned. "I'll take that as a yes, then! Okay, hold up," she repeated happily. "Maybe you missed all the spooky theorizing we were doing up top by the door, but I think..."
The stairs wrapped around for three more turns after the crystal room, the temperature plunging as they delved into the ground. Fewer pipes and apparatuses littered the walls, with the shaft's dominating feature instead being the snarl of massive cables feeding upward into the core. For the last revolution, the walls dissolved entirely, replaced with more steel mesh beyond which a vast cavern was visible, the bottom of the shaft hanging into it like a sack attached to the ceiling.
Starlight's eyes flickered from wall to wall as she stepped onto the solid floor, suspended at least two stories above the bottom of the room beyond. It was dimly lit, but not so much that she couldn't see the edges. Spread beneath them was a five-by-five array of rectangular pillars, laced with crystals and wires and protruding like spikes from the rough-hewn stone floor. She had little doubt that they were spikes, driven far below the surface as some kind of probe. If Valey's explanation was accurate, they would be what was drawing energy up from the ground.
From the top of each, a thick cable snaked, coming together in a knot that fed up through the shaft floor, through another podium, and upwards to the crystal in the room above. Starlight stopped, staring, mostly because Valey had stopped too.
"So..." Valey licked her lips, then pointed to a small door at the side of the shaft, leading to a ladder to the stone floor below. "Looks pretty dark and creepy down there. Who wants to bet there's a hidden door at the side of that room, or something?"
Redshift snorted. "If the generator is locked to keep ponies from finding something, why would it be hidden now that we're inside? I don't see anything at all."
"I do," Maple softly said. "Look at this."
She trotted around the podium where the twenty-five columns' cables were bound into one, pointing to its far side, where a massive breaker switch sat. Valey squinted at it. "Looks like some sort of master power switch," she mused. "Since it's on the main cable, and everything..." Her eyes narrowed suspiciously. "And it's off."
"Well, if the generator is broken-" Redshift began, before Valey cut her off.
"Nope!" The batpony raised a hoof. "If nobody could get in here after it was broken..."
"Then nobody should have been able to turn it off," Starlight growled. "Which means it's probably not broken."
Redshift blinked. "Huh?"
"She's right," Valey said, nodding to Starlight. "Think about it. Main power switch is off, right? Implies someone came in here to turn it off. You said this thing has been failing, not completely dead, which implies that it can't have been off for longer than whenever you last had power. I mean, that crystal up there still had some juice in it! So why would someone turn it off?" She took a step closer. "Could be that they're maintenance, and needed it off to work on it. But that door doesn't open for maintenance, and if someone was fixing this, Spirit or Sky District, they'd be letting the city know. The only other explanation..." She reared up, seizing the lever in two hooves. "Is that it's not actually... broken!"
CH-TUNNNGG!
"Valey wait-" Maple held a hoof out to stop her, but it was too late. There was a shower of electric-blue sparks, and with a tremendous thrum, the central cable shook visibly. The room rushed, then whirred, then settled to a soft humming. Three seconds later, a soft orange glow faded into existence, dormant strips of lighting coming to life.
Valey smirked proudly and thumped a hoof against a stunned Redshift's back. "Well, that worked. Congrats, you've got power again, kiddo! Go me, right?" Her smile held at first... and then slipped away. "Oh, hey, I bet that's what was in here that someone didn't want anyone to find."
At that moment, they were interrupted by the clatter of hooves against metal, coming from the staircase. They stopped once the owner reached the bottom. A second passed, and then a loud, slack-jawed voice managed, "Well well, this sure is a shocking twist! How ever did you kids get in here!?"