"Diamond?" Sparklebright called again while ducking her head under a wooden support beam. "Diamond Tracer, would you just say something for pony's sake?" Like the dozen or so times before, she received no answer.
However, she had advanced far enough into the tunnel by now to pick up the rhythmic clacking of metal on stone from further ahead. Her anger being very palpable at this point, Sparklebright quickened her stride as much as she could, while still being mindful not to bump her head against the low ceiling or stumble over the minecart tracks. The clacking grew louder, until Sparklebright could tell that only one more bend of the tunnel separated her from its source. But when she turned the corner, she stopped abruptly, and her eyes widened in disbelief.
"You're still not done?" she yelled.
Diamond Tracer turned his head towards her and gave her a very annoyed look. Then he carefully put down the pickaxe he was holding between his teeth, and said, "Do you want me to do it fast, or do you want me to do it right?"
"Is there a third option? Like, doing a decent job without taking a million years to get finished?" Sparklebright said. "We're on a schedule here Diamond Tracer. This shipment should arrive at the capital by the end of the week, and they are already short on building supplies from what I hear. Stop being so darn fussy about your work, and just..."
Diamond Tracer had taken up his pickaxe again, and while Sparklebright was in the middle of her lecture, he removed one more sliver of stone with an almost tender looking peck of his tool. Immediately, a chunk of crystal almost twice the size of Diamond Tracer's head detached itself from the wall, and landed on the tunnel floor with a heavy thud.
Diamond Tracer regarded the fallen crystal with a quick nod of satisfaction. Then he looked at Sparklebright and grinned smugly around the handle of his pickaxe.
That little display had somewhat taken the wind out of Sparklebright's sails, so she simply said, "Just wipe that hay-munching smile off your face and help me load this thing up."
Together, they heaved the crystal into the nearby minecart Diamond Tracer had filled up over the course of the day, and started pushing the miner's daily yield towards the exit.
"Oh, don't you look ever so pretty you little darlings?" Diamond Tracer cooed as they pushed, while gently stroking one of the crystals lying before him in the cart. "Soon you'll get to see the Crystal City. I know you will absolutely love it, and I'm sure they will turn you all into something wonderful."
Sparklebright just stared straight ahead with a deadpan expression on her face. "I don't say this nearly enough Diamond Tracer, but you are a weird guy, and you seriously creep me out at times."
"I just take pride in my work. Nothing wrong with that if you ask me." Diamond Tracer said.
But when they turned the corner behind which Sparklebright had found her fellow miner, both ponies suddenly fell silent. A few steps ahead of them, one of the crystal lamps that lit the mine was spilling a pleasant yellow light over the walls of the tunnel. But beyond its sphere of illumination, everything disappeared into darkness.
Neither of them spoke for several seconds, and they just stared into the blackness before them.
"Lamps must have gone out," Sparklebright finally said.
"Yeah," Diamond Tracer agreed. After a few more moments of silence, he added, "Those lamps don't really go out though."
"Evidently they do." Sparklebright replied. Then she lifted her front legs off the minecart and started walking down the tunnel. "Wait here, I'll check it out."
"Wait, what?" Diamond Tracer said alarmed. "Come on, let's just push the cart through. It's not like we can get lost."
"We can't just push the cart through a dark tunnel. What if there's something on the tracks? And I don't really remember if all the switches are in the right position" Sparklebright said. "I'll just walk ahead and see if I can get the lamps going again."
"How?" Diamond Tracer asked.
"I don't know," Sparklebright shot back. "I'll... poke them or something."
Diamond Tracer did not look very happy, but he nodded. "Just watch yourself and get back quickly, all right?"
"Hey, come on Diamond. It's just a dark tunnel. No big deal, right?" Sparklebright said, trying very hard to sound nonchalant.
But in truth, something about that darkness made her feel uneasy. She just didn't know what it was. Before she entered the unlit portion of the tunnel, Sparklebright took a deep breath, as if she was preparing to dive into a black pond, all the while trying not to think about how the borders between light and dark seemed to be much more clearly defined than they should have been.
When she stepped into the darkness, it felt like walking into a bank of thick fog. Sparklebright could see absolutely nothing in front of her, and she had to keep sweeping the wall to her left with her hoof while she was walking to even find the defect lamp she was searching for. But even when she held the crystal right in front of her face, the darkness around her was so absolute that Sparklebright couldn’t even tell it was there. After a bit of fumbling and prodding, all she could determine was that the crystal had a long crack along its center.
"This lamp is busted," Sparklebright called back to Diamond Tracer. "I'll check a bit further and see if I can find a working one."
Then her hoof bumped against something lying on the tracks, and Sparklebright let out a frightened yelp.
"Sparkle? Sweet Harmony, are you all right?" came Diamond Tracer's worried voice from behind.
Sparklebright's heart was hammering within her chest, and she frantically swiped her hoof over the tracks in front of her. When her hoof made contact with the object once more, she let out a wheezing breath she did not know she had been holding in.
"It's fine," she called, her voice sounding a little shrill. "I'm fine. Everything is fine. Just some debris lying on the tracks." She forced herself to bark out a quick laugh. "You know what Diamond? I'm just gonna clear this away, and then we'll push the stupid cart through. It's like you said, not like we can get lost, and now that I think about it, I'm pretty sure the switches are set right." That decision bolstered her confidence somewhat, and Sparklebright quickly began to push the pile of rocks off the tracks.
The rocks pushed back.
Sparklebright stumbled backwards and opened her mouth to scream, but the thick blackness that surrounded her suddenly seemed to pour into her mouth and nose like pitch, and did not leave her enough air to even breathe. She heard and a noise like rocks grinding against rocks in front of her, and the last thing she knew was something heavy hitting her in the side of the head with bone-crushing force.
"Sparklebright?" Diamond Tracer had only heard quiet grinding noises and a few dull thuds from the tunnel since his friend had stopped speaking. "Is it much? Do you need help?"
Only the quiet grinding answered him. He thought that it sounded closer than before, but that was surely just his imagination.
Diamond Tracer laughed nervously. "Alright. I get it. Sorry I didn't answer when you called earlier. Won't happen again, I promise." He peered into the tunnel before him. "Now please, say something. This isn't funny, Sparkle."
Something lashed out from the dark maw of the tunnel and headed straight for Diamond Tracer. It looked like a thin tendril of black smoke, and just when Diamond Tracer thought that it would hit him right between the eyes, it suddenly plunged downwards and latched on to the crystals in the minecart instead.
The magnificent crystal Diamond Tracer had so patiently liberated from the rock immediately darkened and shattered, and he only saw the pieces twitch before a second tendril hit the still working crystal lamp and plunged the tunnel into smothering blackness.