Sweetie Belle had expected class to drag on and on about pieces of information that she really didn't care about, but much unlike pony school, Diamond Dog school only seemed to last a couple of hours. Mami taught them how to identify the differences between gold and pyrite, and the best places in the tunnels for mining diamonds, and then she sent them on her way. There seemed to be some sort of contest in the class; whoever brought in the most gems got the highest grade, or something like that.
Of course, Sweetie Belle had no intention of going out to dig in the dirt. She needed to talk to Sparky, who, quite surprisingly, was trying to get away.
"Hey!" Sweetie Belle squeaked, grabbing his arm as he got up from his desk. "We really need to talk, and you said after class."
Sparky whimpered and flattened his ears against his head, and then sat back down in his seat. Killer, doing cartwheels over the desks came over and plopped himself down in front of Sweetie Belle.
"Hey Sweetie," he said, excitedly, "we're heading to the West-North-West mines to try and find some sapphires! Are you coming with?"
"Sorry, Killer," Sweetie Belle said, "I just need to… er… get settled in. Diamondville is so much bigger than where I'm from, and Sparky has offered to show me around!"
Sparky whimpered again, and tried to make himself appear smaller in his seat. Killer's eyes narrowed and he turned to Sparky and growled, in a very nasty manner.
"If you hurt her, Sparky," he barked, "I swear to Dog -"
"Killer," Sweetie Belle frowned, crossing her arms, "everything will be fine. Go have fun with Maya and Daisy!"
Killer whimpered an apology, and then ran straight for the door, with Maya and Daisy following close behind. In a few more seconds, with the exception of Sweetie Belle and Sparky, the class room was void of living creatures.
"Now we're alone," Sweetie Belle sighed in relief, closing the door, "so we can talk."
Sparky nodded and whimpered, still trying to hide beneath his desk. "What did you want to talk about?"
"Do you remember me?"
Sparky looked into Sweetie Belle's eyes and nodded. "You're the pony that I bit last night, right?"
Sweetie Belle nodded. "I was a pony, but now I'm a Diamond Dog," she growled, crossing her arms. "The only possible reason I can tell for my less than fortunate transformation is you biting me!"
Sparky whimpered again, and winced a little at Sweetie Belle's sudden aggressive tone. "Sorry," he whimpered, "but in my defense, I did ask you to stop petting me."
"That doesn't mean you should bite me!" Sweetie Belle growled and tugged her ears angrily. "Now I'm going to be a Diamond Dog forever! My own sister attacked me when she saw me!"
Sweetie Belle coughed a couple times, and then couldn't hold back the tears that were hanging in her eyes. She fell to the ground and held her face in her massive hands, and sobbed. She let the tears flow out of her, rolling down the fur on her face and splashing onto the ground.
"I'll never be able to see my friends or my family ever again, and it's all because of you!" She cried, wiping her eyes on the back of her massive paws. "You did this to me."
Sparky whimpered again, but he didn't deny that he understood it was his fault. Instead he nodded, and silently admitted that, if he go back in time, he would have stopped himself from doing it to begin with. He didn't like seeing anyone or anypony being hurt, that's just who he was.
"If it's any consolation, you're not completely a Diamond Dog," Sparky whispered, twiddling his thumbs nervously.
Sweetie Belle's more sensitive ears picked up Sparky's words, in between fits of sobbing, and she lifted her head out of her paws and stared at him. "What do you mean I'm not completely a Diamond Dog. Last time I checked," she added, quickly examining her body, "there isn't an ounce of me that is pony!"
Sparky nodded. "It's kind of complicated. We're Equinines," he said, almost too quietly to hear. "During the day, we're ponies, but at night or in the complete absence of sunlight, we're Diamond Dogs. Biting you gave you my curse, and I'm really sorry."
Sweetie Belle just stared at Sparky in mild disbelief. She didn't quite understand what Sparky was saying. Equinines? What the hay are those? She shook her head violently, as she tried to process the information, but inevitably fell on her back and groaned in annoyance. "I don't understand what you're talking about."
Sparky got up from his desk and sat on the floor, next to Sweetie Belle. "I know this is a lot to take in, but your entire life isn't completely over."
"I'm a pony during the day?" She asked, trying to wrap her head around the scenario.
"And a Diamond Dog at night," Sparky nodded. "Of course, if you ever go underground, even during the day, you'll almost immediately turn into a Diamond Dog. It's the absence of sunlight that causes our transformation into Dogs, rather than moonlight, though from what I've been told moonlight can definitely accelerate it."
Sweetie Belle blinked a couple times, letting a few stray tears escape her eyes. She could go home? She could see Rarity again! She could be with her mom and dad, and Apple Bloom and Scootaloo! Her life wasn't over!
"We have to go to the surface!" Sweetie Belle squeaked, hopping to her feet. "I have to be up there when the sun rises!"
"Digging up is a lot harder than digging down," Sparky explained, "but if you really want to, I'll help you. I know of a tunnel that leads right under the outskirts of Ponyville."
Sweetie Belle couldn't contain her jubilance, as this was the best news she had heard all night. She was going home! She could explain everything to Rarity and make everything okay again! Nopony would need to worry about her! And Scootaloo and Applebloom! They'd understand what was wrong with her! They might even be able to help her find a cure or a countercurse!
"What are we waiting for?" She squeaked hopping to her feet. "Let's go! Let's go! Let's go!"
Sparky nodded, and then grabbed her hand. Sweetie Belle blushed at his touch but didn't ask him to stop, and she simply allowed him to lead her out of the classroom, back out into the massive cavern of Diamondville, and through the snaking streets. At the back of her head, Sweetie Belle knew they were heading east. She wanted to think about how she knew that, but she felt it was just her Diamond Dog instincts telling her a direction, and was absolutely harmless.
Several of the other Diamond Dogs caught their eye as they ran past, but Sweetie Belle ignored them and continued to let Sparky pull her through town. When they started reaching the edge of town, buildings were replaced with holes in the ground and tunnels in the cavern walls.
"We'll have to dig upwards in that one," Sparky said, pointing to a smaller cave. "Come on!"
As soon as they were in the tunnel, Sparky let go of Sweetie Belle's hand and started attacking the cave ceiling with his razor sharp claws. The cave seemed to be made out of ancient and well-formed stone, yet Sparky was having no trouble digging through the surface. After a couple minutes, he broke through to the dirt on the other side.
"This is where it gets kind of tricky," Sparky whimpered. "You'll have to stand on my shoulders and make this tunnel big enough for me to climb into, then I can make it longer and start digging upwards."
Sweetie Belle nodded and climbed up onto Sparky's shoulders, using the tunnel he had just created to support her weight, and then began to dig. She really didn't like digging, as it was getting dirt under her claws and all over her fur, but she simply allowed her instincts to take over and started grabbing large pawfuls of dirt, tossing them to the side. It was slow going, and it was hard staying perfectly balanced on Sparky's shoulders, but after nearly thirty minutes of straight digging, she finally had made the tunnel long enough for him to climb into.
"Good job, Sweetie," he smiled, and jumped straight into the tunnel. Unlike Sweetie Belle, who had been slow and steady with her digging, Sparky was fast, throwing several pawfuls of dirt out of the tunnel with each second. After a few seconds of digging, Sparky reached down, out of the tunnel, and grabbed Sweetie Belle's paw, pulling her into the tunnel with him. "Just dig your claws into the wall, like this," he said, demonstrating, "and they'll be able to support your weight. And whatever you do, don't look down."
Sweetie Belle nodded, and followed Sparky up the tunnel as he continued climbing up the tunnel, making it longer and longer, reaching up towards the surface. Sweetie Belle lost herself in the tunnel, becoming one with the cave wall. Time seemed to move slower and faster at the same time, and in some ways it felt like time didn't even exist at all. It wasn't a scary feeling, but it was…
Disturbing.
She didn't like how comfortable she felt while digging a tunnel. She didn't like the way that digging felt like safety in and of itself. She didn't want to like it, but she did.
She lost track of how long they had been digging, but when they finally broke through the surface, there were thin beams of sunglight shining through the tunnel.
"Get out quickly!" Sparky shouted, clambering out of the tunnel. "Before your claws turn back into hooves!"
Knowing that her Diamond Dog claws were the only thing keeping her pinned the tunnel wall, Sweetie Belle tried to hurry as best as she could, but she was already too late. Already her claws were shrinking, turning back into hooves. She could feel her horn growing back out, her fingers merging into a singular digit. It was getting harder and harder to climb.
Her tail changed shape, reverting back into the fluffy pink tuft of fur that she loved so much. The shaggy diamond dog fur that coated her body shrunk away, quickly being changed back into the bright white coat that was so very much hers. She could feel her jaw changing shape, and her vision darkened as her eyes reverted back into those of a pony.
And her claws were failing her.
"Sparky! Help! I can't on much longer!" She cried, barely able to hold on to the cavern wall.
Suddenly, a pair of grey hooves shot into the tunnel, grabbing Sweetie Belle and dragging her up and out. "I've got you!" She heard Sparky say, in a softer, more pony-like voice. "You're okay!"
Sweetie Belle once again stood on four hooves, admiring her reverted body, and allowed a few happy tears to roll down her cheeks. She was filthy, and probably stank of Diamond Dog, but she was okay, and a pony! She could go home to Rarity and explain everything!
But what about Sparky?
Sweetie Belle turned around and looked at Sparky, who was trying to hide behind a tree. "What are you doing? Get over here and let me thank you properly!" She cheered happily, waving him over.
"I don't want you to see me like this," Sparky whimpered.
"Oh come on, you can't be that ugly, can you? I mean, you were a rather cute Diamond Dog, after all."
A grey coat and yellow mane peaked out from behind the tree, and Sweetie Belle felt her jaw hit the ground.
"Storm Spark?!"