To Professor Dubious' credit, unlike certain of his scholarly colleagues he did not scream like a filly.(1) Truth of the matter is that he had a rather stallionesque bellow of terror. Its manliness was unfortunately offset by the fact that he ran like a complete sissy.(2)  Mind, he wasn't exactly in a position to take any criticism on his technique at that moment as he was extremely busy trying to stay quite literally one step ahead of a flying, polychromatic ball of homicidal pony rage.

"Come back here, you coward!"

"AIEEEEEEE!"

He didn't know precisely what happened. He'd heard that Twilight Sparkle had arrived and had trotted up to the front entrance to greet her with some data he'd uncovered, to find her taking a small herd of her friends on a tour of the facilities. Miss Sparkle had called out, greeting him by name. The rainbow-maned pegasus with her had whipped her head about to gawk at him, an expression of absolute astonishment on her face. The moment she'd clapped eyes on him that expression of astonishment had morphed into one of red faced fury. The next thing he knew he was running for his life, the mare right behind him, screaming death threats with every breath.

The Professor of folklore dodged amongst the stacks, desperately trying to evade Rainbow Dash. Thus far he was lucky, as the cursing, fuming pegasus had been stymied at maneuvering in between the crowded bookshelves and was too angry to realize she could fly over them. His luck ran out when he finally took a wrong turn and found himself at a dead end. He turned and stood stock still, terror on his face, but determined to face his onrushing doom. He could almost see flames in the onrushing pegasus' eyes--

"Rainbow Dash, NO, Let him LIVE!!"

At the last second the pegasus was snagged by a lasso, jerking her to a halt. Two of the royal guard and at least two other mares tackled her bodily and dragged her to the floor before she could reach him and kill him. Even then the feisty female thrashed and fought, trying to drag herself within hoof's reach of the cringing scholar. She only ceased struggling when one of her friends, a white unicorn mare with a purple mane,  magically upended a water cooler over her. Spluttering and choking, she finally stopped fighting. The others climbed off her and let her to her hooves. She was far from completely calm, but she had at least regained control of herself. She shook the water out of her mane and glared poison daggers at Dubious, chest heaving as she breathed.

"Rainbow Dash, What in Tarnation is this all about?" the earth pony who'd lassoed her demanded in an Apple clan drawl.

"Professor Dubious, what is this all about?" Twilight demanded at the same time.

"I would like to know that myself!!" Dubious huffed, trying to straighten his jacket. He glared at the pegasus mare. "What in Equestria did I ever do to you, young woman?"

"What did you do? What did you do??" she bellowed. "You ruined my life, that's what you did!!" She lunged at him. He whinnied in fear, shrinking back against the bookcases. The guards managed to restrain her.

"What? How did Professor Dubious ruin your life?" Twilight said, incredulous.

"You know my cutie mark story," Dash growled at her, pushing the guards away. "I was the first pegasus to do the Sonic Rainboom. Ever! I shoulda been famous all over Equestria-- I shoulda been a shoo-in for the Wonderbolts right outta flight school! And I woulda been if it weren't for HIM."

Dubious' confused expression turned to one of shocked recognition. "You? You were that filly who--" he clammed up.

"Yeah, THAT filly," Dash snarled.

"Okay, what?" Twilight asked noone in particular.

Dash rounded on her. "So I won that race with those three jerks," she said. "And I pulled off a Sonic Rainboom. Right? I was in the papers the very next day. And the very next day, Professor Plothead here--" she jabbed a hoof at the Professor-- "starts doing the rounds, telling everyone that I FAKED IT!"

There was a gasp. Everypony turned to look; it was Fluttershy of all ponies, gaping at the Professor in shock. "That was him??" she asked Rainbow Dash. She glared at Dubious so fiercely the professor could almost swear his eyebrows were smoking. "You horrible pony!"

"You know him too, dear?" Rarity asked in surprise.

"How could anypony fake a Rainboom?" Applejack demanded, baffled.(3)

Fluttershy turned to the others. "When Rainbow Dash did the Sonic Rainboom, Professor Dubious  came out and did an investigation. Then he went to all the newspapers and the radio station and everypony, claiming that there was no way she could have done it... that something else had caused the Rainboom and she had just claimed credit for it."

"There was no proof!" Dubious shouted. "No photographs, no reliable eyewitnesses--"

"There were plenty of eyewitnesses!" Fluttershy said, stamping a dainty hoof for emphasis. "You just came around and asked all sorts of nasty questions till you got them to contradict themselves. I know, you did it to me too!"

"I-"

Fluttershy turned back to her friends. "The next day all the papers were running stories about how it was all a hoax," she said unhappily. "Poor Rainbow Dash's confidence was shattered. No matter how hard she tried she couldn't repeat the sonic rainboom."

"I was a laughingstock," Dash said. She had her back to the group, her head down. " Everypony thought I was a liar and a blowhard. Flight camp sucked. Flight school was even worse. The only ones who'd even hang with me were Gilda and Fluttershy. Even the instructors were always giving me horseapples about it. I had to drop out of flight school because I couldn't take it anymore." She looked over her shoulder, sneering at the frazzled professor. "The only work I could get was as a cloud-pusher... I had to transfer all the way from Cloudsdale to Ponyville just so I could start over. All because of you."

Dubious took on a haughty tone. "I only reported the facts," he said in a longsuffering tone. "Nopony actually SAW you do the sonic rainboom, they just attributed it to you because you were flying in the same general area."

"Hundreds of ponies saw me do it!..."

"Hundreds of ponies heard a big boom and saw a flash of rainbows in the sky," Dubious said with the air of someone explaining  a regrettable truth to a foal. "I saw it, too. But nopony could have possibly seen what caused it regardless. The epicenter was nearly nine miles from the nearest pony-- even if a pony had caused it, they would have been too small and too distant to see--"

Dash whipped around, teeth grinding. "OH, so I wasn't CLOSE ENOUGH, was I?" Before anyone could move, she'd grabbed the condescending scholar around his middle and flown for the front door. In alarm her five friends ran after her. They burst out through the front doors just in time to see Rainbow Dash take a ninety degree turn straight up into the sky. The professor's screams dopplered into inaudibility.

"Ooo, this isn't good," Pinkie Pie said.

Professor Dubious couldn't recall the last time he'd screamed so much. That time when he was six on the Dizzyworld roller coaster didn't even come close.(4) They finally stopped climbing into the sky at least a mile above the cloud line. "So nopony was close enough to see, huh?" the mad mare said in his ear. "Well lucky you, now you're gonna see one up close and personal!" With that, they flipped over and began plummeting to earth.

No. Rocketing. Accelerating faster and faster by the second. Dubious caught his second wind--- largely because it was being blasted up his nostrils--- and started screaming again. "Keep those eyes open egghead!" Dash shouted in his ear, barely audible over the rushing of the wind. The roaring grew louder; he couldn't even hear himself screaming anymore. His bones rattled in the turbulence. His eyes teared up;  his vision blurred; was he blacking out or was the air ahead starting to turn white?  He could see the jagged spires of the crystal city rushing up to meet them--

Then the world exploded.

It was loud, a sound so loud that it was beyond sound; more like a noiseless whump that he felt in his very bones. There was a flash of white all around them, laced with radiating needles of color. Then they were through the center of it and out the other side, the air so clear it was like crystal, still racing towards the ground straight as a lance, the turbulence gone.

He felt the pegasus' muscles strain, pulling them up in an innard-punishing 180 turn, racing back up towards the sky, towards the ever-expanding ring of rainbow colored light that now stretched across the sky. He could see their rainbow contrail arcing from the center of the ring...

Then and only then did he finally hear the BOOM.

They flew in a wide, gentle loop, rainbow light trailing behind them, bleeding off air speed till they finally glided back to their starting point at the front step of the library. Rainbow Dash floated in and gently set the Professor down on the ground, in the middle of the gaping crowd of onlookers--- which included Roller Reel with his ever-present camera. "There," she said, smugly tossing her windswept mane. "That good enough for ya?"

"If it ain't, I got it on film for him," Roller Reel said. "That was awesome!"

Professor Dubious was a sight to behold. He stood there, splay legged.  His mane and tail were frazzled, his tweed jacket was a rumpled mess, even his bow tie was violently askew. His eyes were round as saucers, his pupils pinpricks. The only sound that came out of his open mouth was a dry, thin "eeeeeeeeeeeeeee...."

Twilight Sparkle sighed and stepped up to the shattered scholar. "Word to the wise, Professor," she said gently in his ear. "Be careful when you demand proof. You just might get it."

It was a short while before the Professor regained his composure enough for the progress meeting. After a few cups of strong tea, several donuts, and a brief session with a portable steam iron he was back in the game. The scholars and their interns were all gathered around a large table set in the middle of the main area of the library. Books, scrolls and writing implements were in abundance, and several of the magical workstations were up on the table and operating. Illusory scrolls and images hovered in the air.  The head of the table was dominated by an enormous chalkboard and an equally enormous map of the Crystal Empire. Twilight stood at the head of the table, a pointer grasped in her magic.

"So let's go over what we know already," she said as Roller Reel's camera whirred. "We have determined thus far from repeated references in various records that the lost tomb is located somewhere in the Ghibli Hills." The tip of her pointer traced a half-circle around the edge of the map. "Unfortunately the Ghibli Hills is a range that surrounds the Crystal Empire to the North, East, and West. Not exactly a small territory to cover.

"The objective today is to see what we've all gathered so far, see if any of it narrows the search down a little. So," Twilight said, putting the pointer down with a thwack. "Anypony have anything to report?"

One of the interns raised a hoof. "Well, our group has found several references in old ballads to 'the Seven Hills," he said, consulting the papers in front of him. "Three original references in Diamondhoof's Odyssey, two more in the Ode to the Forefathers and the Ballad of the Crystal Stair by Crystal Singer, which specifically say "The Seven Ghibli Hills, under which our forefathers sleep."

Another pony further down the table spoke up. "That would correspond with something we found," he said. His horn glowed and an illusion flickered to life over the center of the table. It was a circle with seven smaller dots inside it in a circular pattern. It spun slowly so that everypony could see it.  "This is the royal seal of the Crystal Empire, or at least it was circa the Pre Sombran era," he said. "The seven dots were originally seven gemstones, supposedly representing the seven districts of the Crystal Empire and the seven noble houses that ruled them, or so the common wisdom went. However, it's not the original seal." The image changed; the dots changing to gemstones. Then it changed again... and the gemstones were no longer in a symmetrical pattern. "This is the seal, some two hundred years pre-Sombra. It was changed to the newer layout because some of the seven houses complained that it implied they were unequal. But the "random" pattern is far older. "

The illusion changed again. Now the seal was decorated with seven indentations, shaped like the letter V. "This is the oldest example of the seal-- used on a royal document some 1,500 years pre-Sombra. Prior to that the royal seal was merely the king or queen's hoofmark in ink. Note that the pattern is still the same. Every sample between 50 years pre-Sombra and 1500 years pre-Sombra has that layout. This seal, as shown, was used during the reign of Queen Vivid Vision, hence the letter V.

"I think I know where this is going..." Rainbow Dash singsonged.

"With the help from Professor Dusty Bones' group," here he nodded to a group of ponies on the other side of the table who returned the gesture, "I cross-referenced for any stories from Queen Vivivi's reign. According to legend, Queen Vivivi ascended to the throne after her husband's death and burial in the tomb. At his funeral she, quote, 'stood in the hill o'erlooking that mighty tomb, and sealed its hills in her memory."

"And I'm guessing that--" Twilight began.

"--that this was a mistranslation," A crystal pony mare said. "She didn't seal the hills in her memory, she--

Twilight finished it with her. "--Put the memory of the hills in her seal." Twilight clapped her hooves together. "It's a MAP!" Congratulations and cheerful exclamations rose up around the table.

"Yeah, now all we have to do is figure out which seven hills it is," Spike muttered. The elation around the table diminished somewhat.

Twilight's eyebrows leveled. "True," she sighed. "Has anyone in the Crystal Empire done an aerial survey?"

Rainbow Dash went airborne. "Hey, I'm your mare for the job," she said confidently. "Just gimme a camera and I--"

"Perhaps we should narrow down the area before trying to survey a thousand square miles of hilly country?" Applejack said wryly. "Yer fast, sugarcube, but we could be takin' photos from the clouds and countin' hills till the next millenium."

Dubious cleared his throat. Everypony turned to look at him. "I think I have something that might narrow down the search," he said. "At least by two thirds, anyway." He pulled out a tape recorder. "As I told you before, my specialty lies in oral history. As a little side effort, I have been going about among the general populace, holding little interviews, recording any folklore they cared to recite for me-- stories, poems, songs, traditional superstitions and so forth." He paused and cocked an eyebrow. "For a side note to any crystal ponies in the room, no, your grandmother was wrong, swallowing a fire opal will NOT make it bigger." Several stallions in the room suddenly looked uncomfortable, while more than a few mares smirked.

"Ahem. Anyway, I happened to come across a rather elderly mare on one of my perambulations who was so kind as to recite a song once sung to her by her grandmother, when she was just a filly. I think you might want to take note." He pressed the PLAY button with his magic.

A high, quavery voice rose up from the device, filling the air.

"I remember now my Summer's love,

Though now I feel late Winter's chills,

I watch the sun set behind the Crystal Spire,

as I rest upon the Seven Hills..."

"I haven't heard that song in years," one of the crystal ponies said, reminiscing. "My mother sang it as a lullaby.. she didn't know the words, though..."

"Yes!" Twilight said. "The singer would have to be looking West to see the sun set, which means they were sitting East of the Crystal Spire. The Seven Hills are in the Eastern Ghibli Range!" She spun around and drew a circle around the hills on the east side of the map. "Quick, get out the maps of that area and start looking, everypony!"

Several hours of searching later, they had nothing to show for it. Twilight had even resorted to sending Dash on an ultra-high flight with an instant camera; still, no results. Everyone was poring over maps and photos old and new; they would have been tearing their manes out in frustration if they'd had fingers. There were a few groups of hills that looked similar, but none matched the layout shown in the royal seal.

Of course the breakthrough came from Pinkie Pie. "This would be a lot easier if it wasn't backwards and upside down," she mumbled, staring with popped-out eyes at a handful of aerial photos.

Everypony froze. "...What did you say, darling?" Rarity asked tentatively.

"I said this would be a lot easier if it wasn't backwards and upside down," Pinkie said. "Why?"

"Where do you get that from?" Twilight said, baffled.

"Well, duh, silly, it's a royal seal, right? Like a rubber stamp for fancy ponies! Look--" she zipped to the library's checkout desk, grabbed a rubber stamp, and zipped over to Twilight. "See, this is the OVERDUE stamp, but look-- its backwards," she pointed with her hoof at the underside. "Which is a good thing because nopony would know what EUDREVO means--"

"Pinkie, I'm sure Professor Dusty Bones flipped the image... over... before he..." Twilight had to pause because the pony in question was calmly, quietly thumping his forehead against the table.

"Backwards..." he groaned, banging his head again. "Of course..."

Twilight facehooved. "Okay. But upside down?"

"Well yuh," Pinkie said. she pulled out a picture of a crystal pony in royal garb. "See? She's wearing the seal as a pendant around her neck!"

"Aaaand...?" Twilight motioned for her to continue.

"Of course," Rarity said suddenly, her face lighting up. "She wore it as a memento, so she would remember her husband whenever she looked at it. But the poem, well it implies like it was a spontaneous, romantic gesture--- She must have been wearing it around her neck... and when she held it up to engrave it--" she made a motion as if she was lifting a pendant off her own chest and holding it up in her hoof.

"-- She was holding it upside down," Applejack said, grinning. "Well if that don't beat all! Good eye, Rarity! You too Pinkie Pie!"

Twilight shook her head. "Of course," she said, pointing at the still rotating magical illusion. "Those aren't little Vs, they're little upside-down hills! Professor, can you flip that image around ?" Dusty Bones eagerly complied.

"Wait," somepony shouted. "I've seen those hills somewhere here-- where's that one map, the one with the yellow..." There was a great deal of frantic shuffling of scrolls and papers. "Here!!" a survey map was slapped down on the table.

Everypony, even Professor Dubious, leaned in breathlessly. Wordlessly Twilight levitated a pencil and drew a circle around a tiny, unassuming-looking group of hills. Dusty Bones shrank the illusory seal down and floated it over the map.

It was a perfect match.

"We found it," Twilight whispered. The whisper spread through the group. Twilight repeated herself. "We found it. We found the Lost Tomb of the Founders!!"

A deafening cheer went up. The next instant every pony in the room was bouncing like Pinkie Pie on a double espresso.(5)

Garble signaled for a halt. The sextet of dragons rumbled to a stop near one of the last mountains in the range. "What's up, Garble?" Rockjaw growled. His voice was now an earthshaking rumble.

Garble looked back, grinning. "It dawned on me, we're gonna need a little help picking up all them jewels and gold and stuff," he rumbled back. "And keeping it polished and sorted an' all that other crap, once we got it."

"So?" Grundle said. "We make da ponies do all that."

Garble sneered. "Pffsh, too much trouble," he said. "They're a bunch of whiny pansies anyway... they'd wear out from the work.(6) I got me a better idea."  He pointed to the ground all around the base of the mountain, which was dotted with what at first glance looked like gopher holes, till one realized that said gopher holes were far too large to belong to a mere gopher.(7) He knelt next to one of the holes, and motioned for the others to do the same. "Get ready to grab what comes out," he said. He put his mouth next to the hole, took a deep breath...

"AAAAAAHHHHRRRRRRRRR!!!!!!"

Smoke and terrifying noise poured down into the hole. Screams and yelps of terror could be heard emanating from all the surrounding holes, and suddenly terrified, screaming canine shapes erupted from several of them. "Quick, grab 'em!" Garble yelled. Scaly claws the size of bulldozer shovels lashed out, and every dragon had themselves three or four Diamond Dogs clutched in their fists.

Garble got lucky; He had three in one fist and one, a large black one with a diamond collar, in the other-- obviously the leader of the pack. "SHUT IT!" he roared. The panicked yelping and ki-yi'ing ceased.  He held the pack leader up to look him in the eye. "Here's the deal, mutt," he said. "We're dragons. You're Diamond Dogs. You work for US, now. We're gonna go smash a pony city and take their treasure. You're gonna scoop all the treasure out of the rubble for us, and I mean every. Last. Gem. You count it, and polish it, and carry it, and do whatever else we say."

"What in it for us, then?" The scraggly mongrel asked. Garble shook him like a maraca. "I-i-i j-u-u-ust as-k-i-ing," the diamond dog protested.

"Then I'll make it simple," Garble rumbled, smoke seeping from his nostrils. "You work for us and you get gems. Or you get eaten. Got it?"

The black diamond dog held up a finger. "Actually, that make it sound like if we work for you, we maybe get gems or maybe get eaten. Grammar important to convey correct idea when hnnnnnnngggg," he cut off as Garble began to squeeze. "Hokay, work get gems, no work get eaten, got it Boss," he wheezed. Garble relaxed his grip.

"Good ," Garble growled with a toothsome sneer. He stuffed his new slaves into his makeshift hip-bag and resumed stomping his way. His partners in crime followed suit, having made makeshift bags of their own, and fell in step behind him. "Next stop, the Crystal Empire..."

1)You know who you are, Spell Nexus.

2)The Ministry of Silly Walks had sent him several warning letters already.

3)Some few had tried. One effort had involved a giant vat of rainbow juice and a barrel of dynamite. The results weren't pretty-- well actually they were rather pretty, or at least colorful, but nopony appreciated them much.

4)He'd been too busy puking to scream that much. Dubious really hadn't had a very happy childhood.

5)With all the elated crystal ponies in the room it looked like an explosion at a rave.

6)Not that he, or any other dragon alive, really KNEW that. There is a reason Equestrian ponies lived in a safe, peaceful kingdom free from the fear of enslavement or oppression for thousands of years. There is also a reason that the dragon capital city, for lack of a better term, is built in a crater. These two reasons are coincidentally one and the same.

7)Then again, this was the world of Equestria.