The insides of the cavern looked to Twilight just like any old cave, although Zerephonzidas insisted it was where he wanted to be. The team had begun work on excavating whatever was within. Digger Douglas was making splendid progress.
Rarity bustled past Twilight, holding a basketful of lamps.
“I’m just trying to brighten the place up a bit,” she said. “It’s dreadfully dark in here.”
Twilight had to agree with her. She felt she had to go outside just to feel some fresh air, despite the cold. The caverns were oppressive. There were several that branched off into multiple smaller tunnels filled with strange rock formations. The stone inside was a strange green colour. Twilight had broken a piece off and examined it outside. It was very pretty.
Rarity, Applejack, Rainbow and herself had all set up their tents in the same branch of the caverns. The other diggers were spread out in various places. Fires and heating devices had been set up at various points, and a large cooking area had been set up. The diggers knew how to make the place feel as homely as they could.
“The rock,” Twilight told Applejack, “Is really quite special. I can’t place where it comes from.”
Applejack shrugged. “Didn’t Zereph say that this place used to be covered in sand? Maybe it’s a more desert-y kind of rock.”
Twilight nodded. “I’ve been thinking about that. I’ve been trying to think about what might have caused an entire cave network to move from a desert to a snowy tundra.” She stroked her chin. “I think that Zerephonzidas gave us the answer earlier.”
“Discord,” Applejack said.
Twilight nodded. If there was one thing that could shift continents and turn the world on its head, it would have been Discord’s reign.
The air in the caves was rather stale. Not much wind came in this far down. It was surprisingly eerie at times, but comforting at others. When with her friends, Twilight felt safe. Without them, she felt trapped.
She was even getting used to Zerephonzidas. He was actually rather pleasant to talk to. At the very least, he was the one she could talk about magic about the most.
It must be strange, she thought, to live for over a million years. To witness evolution as it happened. She found she enjoyed listening to him tell her about the development of ponies, and he seemed excited to talk about it.
“What really surprised me was the art,” he had said. “Sphinxes don’t make a lot of art, but I found it fascinating for such an inferior… at the time… species to create crude representations of animals on the walls of caves.” He frowned. “Of course, Discord destroyed most of those, in his stupidity. And naturally, other sphinxes were less than thrilled about your kind’s development.”
“But not you?” Twilight had asked.
“I was interested, shall we say, not thrilled or scared.”
Twilight made her way back to her tent. There, she found Rainbow Dash lying lazily on her bedroll. Twilight snickered.
“Archeology less exciting than you anticipated?”
“The guys here haven’t used a single stick of dynamite!” Rainbow complained. “How are you supposed to clear out whole tunnels in one go without explosions?!”
“Carefully,” Twilight replied.
Rainbow only grumbled in reply.
“Yeah, whatever. At least Applejack’s good for a card game when she’s not helping the others.”
“You could help too.”
“Help what? I’m not scraping rock away with a toothbrush, and I’m sure not going to cook or clean or act like a maid.” She rolled onto her side and picked up a Daring Do book. “Call me if you accidentally unearth an ancient evil or something, okay? Until then, I’m gonna read my book and maybe work out a bit.”
Twilight smiled.
“I don’t think there are any ancient evils here,” she said.
“Yeah, that’s what they say at the beginning of every Daring Do book,” Rainbow replied. She gave Twilight an exasperated look. “Didn’t you read the entire series? You should know this by now.”
Twilight smiled. Rainbow had a point. She trotted away, leaving the pegasus to her own devices.
Applejack and Rarity, by comparison, were far more helpful. Applejack especially. She was stronger than even the largest stallions, and had been a great help in setting up some of the more sturdy supports.
Down in the deepest caverns sat Zerephonzidas. He preferred to keep an eye on the digger’s progress in person.
Twilight carefully navigated the at times slippery passage and found him hunched over a paper, a pen pinched between his claws. His eyes rolled up to meet Twilight’s.
“Hello,” he said.
Twilight gave him a curt nod. “What are you writing?” she asked. “Notes on our progress?”
“Not any more,” Zerephonzidas said, and gestured towards a large pile of diagrams. “A lot of those are based on my memory of previous investigations, but I’ve mapped out the more promising directions to dig.” He turned back to his current writings. “This is a letter to Celestia, if you must know. I intend to send it back with the caravan, if we’re still working here by then.”
“A letter to Celestia?” Twilight asked. “That takes me back.”
“Fond of correspondence?”
“She told me to send her a letter every week after I moved to Ponyville,” Twilight said. “They were, well, the highlight of my week at the time.”
Zerephonzidas nodded. “Well, I don’t tend to send letters every week. More like every five years,” he said. “I think she enjoys keeping in touch more than I.”
“How long have you known Celestia?” Twilight asked.
“Eight hundred years,” Zerephonzidas replied. “It was just as Equestria was beginning to look like it does today,” he went on. “Ponies were replacing the grim and grey houses with colour, and the streets were filling with life. I was very interested in your development by this point. You had evolved from mere curiosity to a truly fascinating culture.”
“I always felt like Celestia was the oldest pony around, but talking to you about the evolution of pony-kind makes her sound practically young.”
“Compared to me, she is,” Zerephonzidas said. “There are many differences between myself and your mentor.” The sphinx grinned. “She’s kinder, for starters.”
“So, what are you writing to her about?”
Zerephonzidas put his pen aside. “The dig site. I’m trying to find the correct words to thank her for locating this place for me.”
“Why not thank her in person when you get back to Canterlot?”
Zerephonzidas’s expression turned dark. “I am not sure I will be returning to Canterlot after we get to the center of these caverns,” he said.
Twilight raised an eyebrow, a sinister feeling creeping up her spine. “Why would you say that?” She remembered her earlier discussion with Rainbow. “Do you think there’s anything… dangerous here?”
Zerephonzidas smiled. “Not to me,” he said. “I may have lost one of my eyes five thousand years ago, but I am still a sphinx, and these caves hold no fear for me.”
Twilight did not point out that unlike him, the rest of the ponies at the dig were not sphinxes and weren’t built like ancient, primordial killing machines.
Zerephonzidas was oblivious to Twilight’s growing worry. “Rather, I simply mean that after I find the answers I’m looking for, I’m… going to want to think about it for a time.” He ran a paw through his mane. “I like to take a long time to mull things over, and I believe that this trip will have given me much to think about. Either because it will be as life-changing as I hope it will be, or because I wasted five-thousand years chasing something that was never there.”
“What do you expect to be here?” Twilight asked. “You mentioned a magical experiment, but you kept things rather vague.” She narrowed her eyes. “It reminded me of Celestia a little.”
Zerephonzidas leaned back.
“Tell me, have you ever given any real thought to immortality?”
Twilight was taken aback. “Um, not really. I just know that Celestia is immortal, and I assume you are too.”
“Do you think you, as an alicorn, are also immortal?”
Twilight had researched this. “No,” she said. “All my studies point towards Celestia and Luna being outliers, unusual among the few recorded instances of alicorns.”
“Imagine you were Celestia for a moment,” Zerephonzidas said. “Humour me.”
Twilight frowned. “Then I’d be immortal,” she said.
“Then, perhaps you can answer this: how would you know?”
The cave fell into momentary silence as Twilight tumbled deep into thought.
“I’m not entirely sure,” she said, after a long time.
“Now pretend you’re me. You’ve lived for over a million years, you’ve seen the rise and fall of species, the shifting of continents. You’ve been there for all of it. Would you say I am immortal?”
Twilight was beginning to get an idea of where the discussion was going. “You don’t know how long you live either,” she said.
“I do not. No sphinx has died a truly natural death. We have died violently, or of poison and disease. Never of old age. Back when there were still enough sphinx around, we would compete to live the longest. As you can see, I won.” He tapped his claw on his table. “The point is, one cannot observe the limits of immortality. To do so, you’d have to spend all of time watching it play out, and time has a tendency to go on somewhat.”
“What experiment happened here?” Twilight asked, feeling very uncomfortable at all this talk of immortality, and time. “What are you looking for?”
Zerephonzidas smiled. “I believe that here, in these caverns, is some information to be had with regards to true immortality. Not the half-immortality myself and Celestia possess. I am looking for traces of the Immortal King, who is as far as I know the only creature to have succeeded in achieving the purest form of immortality, if he even did.”
“You mentioned him before.”
“I did,” Zerephonzidas said. “He was a pony, believe it or not. Yet another fascinating surprise from your species.” Zerephonzidas tapped his claw on the table again. “Tell you what. Despite my considerable knowledge, I would like to hear your findings on the matter.” He rumagged around in a bag, and pulled out a small device. Twilight immediately recognised it as being a thaumometer.
“You want me to perform a magical search?” Twilight asked. “Which one? Elderwood’s? Starswirl Method?”
“Whichever. You should find some magical resonance in the stones here,” Zerephonzidas said. “I have been unable to glean much information I haven’t already known. I’m given to understand you are an expert on magic, however…”
“It is my special talent,” Twilight declared.
“Perhaps you shall find something the old sphinx has not, then,” Zerephonzidas said. He handed the thaumometer to Twilight. “We should have a few days before we get really close to the center of the spell. It seems time and magic has blocked up most of the passageways that were once here.”
Twilight took the device. “Yes, I noticed that the stones were… odd,” she said. “Dark green-ish. I’ve not seen it before.”
“You wouldn’t,” Zerephonzidas said. “Very few spells are powerful enough to turn this amount of sand into glass,” he said.
Twilight’s eyes widened.
“What did you…?”
“If you don’t mind, I need to finish my letter,” Zerephonzidas said. “Besides, I wouldn’t want to put any ideas in your head that might bias your thinking more than I already have.”
Twilight slowly moved away from the sphinx, pushing past the diggers working nearby.
Applejack and Rarity were both standing a ways ahead. Rarity looked at Twilight’s thoughtful expression with some small amount of concern.
“What is it, darling?”
Twilight caught up to her friends.
“I think…” she began, frowning. “I think perhaps the Daring Do books were right after all.” She looked around at the caverns. “This is all much bigger than I expected.”
Rainbow Dash heard hoofsteps near her little corner of the cavern. She didn’t expect much excitement from anypony, so she didn’t bother looking up from her book. She didn’t understand. When she had met Daring Do, she had been on an adventure. Caballeron was there, and so was Ahuizotl. There were giant rings and epic stakes.
Twilight, or Celestia, or Zereph, or whoever had the idea for this journey had picked the most boring… and the coldest… adventure of all time. Then again, cold might help in that regard. Yetis were probably real. Rainbow’s eyes lit up a little as she kept on skimming. It’d be like that bugbear again! She still had a mark from where it had bitten here.
“Hey, RD?”
She should maybe get that looked at, actually…
“...Rainbow?”
Rainbow rolled onto her stomach. Applejack loomed over her like a stormcloud.
“Hey, AJ.”
Applejack ran a hoof through her mane. “Listen, I weren’t gonna say nothin’ ‘bout you not pullin’ your weight around here…”
“It’s their fault if they made archeology boring.”
“...but why’d you have to go and make Twilight all skittish? She’s been starin’ into that doo-hickey for over an hour now, mutterin’ ‘bout all kinds of dark magic.”
Rainbow’s eyebrow raised. “What’s that?”
“She’s all worked up, and I reckon it was these,” Applejack said, prodding Rainbow’s pile of Daring Do books, “That caused it.”
Rainbow snorted. “Don’t blame the Daring.” She turned back onto her back and made a point of mock reading. “Talk to the sphinx-thing. He’s the one that’s acting all manipulative like. Besides, even his name sounds like a Daring Do villain.”
Applejack grumbled and looked to her side. “I tried talkin’ to him. He just told me a bunch of things that didn’t make sense.”
“Classic villain.”
Applejack put her hoof on the top of Rainbow’s book and pulled it down. The pair now looked into each others eyes.
“This is what I’m talkin’ ‘bout. You sayin’ things like that is what puts ponies on edge.”
“I’m not on edge.”
“You’re… really thick skinned.”
“I’m not thick skinned.”
“You are to this.”
Rainbow folded her page and closed the book. “Hey, you guys don’t have to believe me if you don’t want to. I don’t care.” She put her hoof on her chest. “I can deal with anything that comes my way.”
Applejack sighed. “Well, we ain’ t you,” she said. “This place is really givin’ me the creeps.”
“Not you too,” Rainbow said.
“Yes, me too. And Rarity also,” Applejack said. “Rares’ has been spendin’ all day tryin’ to cosy the place up, make it less spooky, but just puttin’ some lamps up ain’t cuttin’ it. I can’t explain it.”
“We’re in a cave, AJ,” Rainbow deadpanned. “Ponies don’t like caves.”
“It ain’t the cold either,” Applejack went on. “It’s like there’s this… I dunno.”
“Noise?”
“I guess, when you put it like that?”
Rainbow grinned. “What a coincidence. There’s a noise here, too. A really annoying, vague one.”
Applejack snorted. “Well, har har,” she grumbled.
Rainbow giggled. “Wanna play cards? I’m bored reading.”
Applejack sighed. “Yeah, sure thing. You mind if I invite Twilight and Rares? They could use a break.”
“Sure, whatever. The more the merrier.”