As for the place, Hesiod asserts that a bronze anvil falling from heaven would fall nine days before it reached the earth. The anvil would take nine more days to fall from earth to Tartarus.

Ho hum, thought Celestia from her perch on high. Yup. Here I am. Kidnapped again. Oh, dear me, what ever shall I do? She managed not to giggle.

“Let the Princess go and maybe we’ll go easy on ya!” shouted Rainbow Dash.

“Hah!” shouted Artifice, the self-styled Mistress of Machinery. “You don’t scare me, pegasus!”

Celestia, for her part, remained silent, hiding her smile. The chain that held her dangling from the low roof was built of thick, heavy steel. It would take all of two seconds for her to melt it to slag, if she were into that sort of thing. It was attached to some huge, clanking, arcane device, the purpose of which eluded casual inspection. Supposedly it would channel all of Equestria’s magic straight into the madmare who built it.

“And it doesn’t matter, because you’re too late! With this final piece, my devious domination device will be complete!”

‘This final piece’ was Celestia’s crown, swiped off her head shortly before the Princess had been strung up.

“Mwahahahahaha!”

Honestly, is that the best ne’er-do-wells can come up with these days? Steal magic thing, rule Equestria? Does she really think that crown has any power in it?

The crown was, in fact, a part of Celestia. A bit of her soul, given form in indestructible golden metal and violet stone. It held no more power than she gave it, which, at the moment, was none. As such, Celestia was fairly certain there was no real threat here. But she played along anyway.

It had been a while since Twilight and her friends had gotten to lay out a good thwarting on some villain. It was good for them. And sure, the damsel-in-distress role did get a bit old at times, but it was worth it to Celestia to let her ponies know that they could get by without her.

And besides, their little battles were just so cute. Maybe the villain, this 'Artifice,' would even learn the error of her ways. Twilight’s friends were quite good at that part. Not that they couldn’t handle themselves if it came down to a brawl, of course, but it was always nice when everypony learned something.

Twilight Sparkle leapt to the fore.

“Alright girls! Get that crown!”

At her word, the entire group jumped into action. Applejack stormed up the stairs, plowing into and through the unfortunate minions who stood in her way. Rarity followed her up, casting a spell into one of the many crystal-laden devices around her. The few thugs who hadn't already been thrown aside by Applejack foolishly glanced into it and were blinded enough that Rarity could saunter by untouched, nose held high. “Hmph,” she said, voice dripping with disdain.
"Ruffians."

A bit of concern showed on Artifice’s face as she watched their progress.

“No matter!” she barked. “Let’s see you get past this!” She yanked back on a lever and arcs of lightning jumped to life at the head of the staircase.

Ahh, thought Celestia. The lightning barricade. Classic. Though it does have a few inherent weaknesses…

Rainbow Dash bolted past the hovering thug-pegasi, zipping in tight circles around them. The resultant multihued tornado flung them in various directions. Fluttershy cringed and tried to look brave as she trailed after.

Artifice growled and threw back another lever. A series of panels dropped open all around the machine-laden dais she perched on, revealing several massive fans. The blades went from zero to really-super-fast almost instantaneously.

Celestia nodded her approval as Rainbow Dash’s rush was slowed to a crawl. Good thinking on Artifice's part. Covering all the bases.

Fluttershy dropped straight to the ground, nowhere near strong enough in the air to handle the fans. Well, discretion is the better part of valor. But there’s still…Twilight was already firing up her horn for a *blink* to the platform on which her latest nemesis stood.

But first...

“Hi!” proclaimed Pinkie Pie pleasantly, hopping happily past Artifice.

“What!? How did you..!?”

Hah! Pinkie Pie. Woe to the villain who forgot to account for the wild card.

“How did I what?” asked Pinkie, reaching past the dumbfounded doctor to nudge the fan lever back into the 'up' position. The fans shut off just as Twilight popped into existence dead center in the platform.

“Give it up, Artifice! We have you surrounded!” Twilight Sparkle smiled with fierce determination, magically throwing up the lever that had activated the lightning wall. Her friends, now free to join her at the top of the stairway, sauntered up at their leisure. Celestia would have stood up and clapped if she weren’t currently bound upside-down by chains.

“No! You'll never stop me!”

The madmare’s horn blazed to life as she shoved past Pinkie. Twilight threw up a shield to ward off the incoming bolt of magic but…nothing came. Artifice rushed straight past her to the little dais where The Final Piece was to be placed.

A feint!

Celestia gasped with more drama than was entirely necessary.

Artifice used the magic she’d stored to grab hold of every lever in the room and threw them down all at once. Just before being tackled by Applejack, she tossed the crown onto its assigned spot.

“HAHAHAHAHA!”

The entire room held its breath in suspense.

“…Ha?”

Nothing happened. Artifice looked up from under her own hooves, and also the earth pony sitting astride her, eyes twitching over her machines in manic desperation.

"No! It should have worked! I thought of everything!"

Celestia almost laughed. Typical, she thought. Leave science to the more-or-less sane, rookie. Instead, she said,

“Excellent work, Twilight! You’ve saved Equestria again!" She gave her student a radiant smile. “You, and all of your wonderful friends, of course.”

Twilight blushed, caught between pride and happy embarrassment. Her friends each followed suit in their own way.

“Oh, it was nothing.” Twilight Sparkle pawed at the ground with one hoof. "I'm just glad we—"

The entire chamber rumbled. It wasn't a mechanical sound. It was deep, and horrid, and implacably malevolent.

“You fools!” screamed Artifice, throwing Applejack off with some kind of newfound hysterical strength. “You thought me defeated so easily!? I’ll show you!”

Celestia tried to say something, tried to be glib, but there was something terribly familiar in that growling, evil sound.

The group of friends glanced about nervously, each looking at Twilight as though she had any idea what was happening. The floor beneath them began to quake. Every device upon it, the fans, the lightning wall, the alarms, everything all fired off at once.

“Wh—” Twilight staggered as gravity gave way to the bizarre magical field the machines were generating. “What did you do!?”

The Artifice let loose another mad cackle. “Oh you’ll see! You’ll all see!” She staggered her way to a big, red, brightly blinking button, using her magic to sort of swim when her hooves could no longer touch the ground. She slammed a hoof down on it, and the look she gave Celestia as she did it chilled the Princess to the bone.

It was cold, and vicious, and perfectly, villainously sane.

“And we’ll all see how long your precious Equestria lasts without you, Princess.”

Bits of dust and broken stone rose slowly past Celestia into a rapidly forming vortex of violent magic and hellish un-light. The chains that held her were already being sucked into the morass. Bubbles of strange, dissonant magic were coagulating on its surface. Celestia broke her staring match with Artifice and looked into it. Her eyes went wide in recognition of what lay on the other side, and then narrowed dangerously as realization hit her. Artifice: Ingenuity, cleverness. Or…a clever trick or stratagem; guile; craftiness. Dammit! She couldn’t believe she hadn’t caught that earlier. Celestia's thoughts raced as her eyes flicked from Artifice’s smug grin to the crown on the dais. Powerless by itself, but a perfect sympathetic link with which to target her. She couldn't dodge this world-rending spell now. She'd let it come too close. She couldn't block it or deflect it away.

Well done, you monster. But if you want to play hardball…

Celestia turned her baleful gaze back to Artifice, looking her straight in the eye as she let some measure of her true might surge into being. Her mane burst into golden flame, her entire body ignited with impossible strength as she snapped hundreds of pounds of steel like so much—

Twilight popped into being atop her, wrapping her legs around Celestia and beating her wings as hard as she could as she tried to drag her Princess away from the twisted magic of the portal.

“Don’t worry Princess, I’ve got you!”

“No! Twilight just g—”

In that moment of distraction, a bubble of noxious ether burst, gushing otherworldly energy over the both of them. Celestia’s attempted protests and warnings were drowned out in the flood. Tendrils of malignant magic boiled out of the other bubbles and flailed blindly for anything they could reach. Celestia despaired, blind and deaf to everything outside the gleefully malignant snarl of the magic that had her. It took everything she had just to shield Twilight and throw her away from the surging portal. She didn’t even know if it worked. The last thing she heard was a scream.

Or maybe...a call?

Celestia drifted in silence. She couldn’t see. For a time, she couldn’t even remember what seeing was like. She floated, blind, numb, and deaf. Or maybe she always had been this way, and was just hallucinating the memories of such strange things as sight and sound and touch. She was alone in this, with nothing but her own muddled thoughts to keep her company. Then even those faded, and there was...

Nothing.

Gradually, her mind reassembled itself.

Celestia opened her eyes, and immediately regretted the necessity of having senses. She might have groaned. She would never remember. Everything felt wrong. Not painful, exactly. Just not like it was supposed to feel. She couldn’t quite remember what things were supposed to feel like yet, but she knew it wasn’t like this.

It was too quiet, first of all. After the mad cacophony of the portal and cavernous, echoing emptiness of her last memory, everything was far too quiet. Utterly silent. No wind. No birds or bugs. The only sound was the rustling of her own body as Celestia flailed to right herself. It was so still that she could keenly feel the rush of blood through her veins, the rhythmic pulse of her heart and breath. This wasn't right!

She blinked owlishly. It felt like days before her eyes could finally focus. When they did, she saw nondescript trees and patches of grass. A few shrubs, here and there. She looked down and found that she lay on a reddish dirt path running through a forest. The light was all wrong here. It didn’t seem to come from anywhere in particular, and it was far too even to be natural. There were no shadows. That meant something…Celestia looked up blearily, and her mind froze in a moment of sublime, perfect, existential horror.

There was no sun here.

Celestia sucked in a panicked breath. She couldn’t see. Through the Sun, her very soul, she should be able to see across the entire world, but all she saw now was the tiny pinprick of space that lay before her eyes. She was numb, and deaf. The borders of her other soul, that of Equestria itself, were suddenly unknown to her. The endless, murmuring hopes and needs of its people were gone. The eternally comforting, guiding, demanding influences of Celestia’s greater souls had vanished, leaving her truly alone for the first time in centuries. Without them, she wasn't a Princess, wasn't a Goddess. Just a pony.

Celestia’s breath came short and sharp as she tried to find some point of focus for her free-falling mind.

The sky was black as the darkest night. More so, for there were no stars. Dead center in that sable sky was a ring of slowly flickering red fire. The inside was empty, an impossible pit of deeper darkness in a sky that held nothing else.

Gears that had been whirring uncontrollably in Celestia mind slammed into place. Her first rational thought was a curse that hadn't been uttered in Equestria for generations.

Shit.

Tartarus. I am in Tartarus. Okay. Alright. Celestia closed her eyes and struggled to control her breathing. It should have been easy, but nothing was ever easy in this horrible place. Her heart thudded against her ribs as she fought against the mortal terror this land inspired in her. Literal mortal terror.

There was no Sun here. And that meant she could die. Without her nation, without her Sun, Celestia was little more than an oversized unicorn with wings.

I am in Tartarus, but that is okay, because I am not going to panic. She tried to take deep breaths, but they kept coming in hard and short and sharp. She shouldn’t even need to breathe. I am going to let myself sit here, and think, and I am not panicking right now.

Sometimes it helped to say these things. They weren’t true, but if she could just fake it until the bad part passed…

It is perfectly reasonable to be scared, because dying is scary, but it isn’t permanent for me because my other souls will bring me back, so there’s really nothing at all to be scared of, right? Right. She took a deep breath, filling her lungs completely, slowly letting it out a few moments later.

Well, there was still the possibility of a long, painful, pointless death at the hands of the monsters here to be afraid of.

That isn’t helping! At the very worst, I’ll wake up tomorrow in Equestria remembering none of this. So...

Another deep breath. This one was calmer.

So, it’s like an adventure. Like one of those books Rainbow Dash likes so much. A quest.

There. That was helping a bit. Celestia attempted to force a bit of levity onto herself.

It could be fun even. No responsibilities. Nowhere I need to be. No tabloids or snotty nobles following my every move. Celestia breathed again and even smiled a bit. No need to behave. Sure, I’m stuck in an absurdly murderous deathtrap where everything, everywhere wants to kill me, but on the upside, there’s no one to worry about but me, for once. Plus… she looked down at her unshod hooves and bare neck. Her usual panoply, the crown, shoes and gorget that marked her as ruler of Equestria, were gone. Like her Sun and State souls, they were a part of that world, and couldn’t normally leave it. And while, yes, that all meant that she was mortal here, it also meant…I get to do it all naked! So that’s nice.

Celestia opened her eyes and nodded to herself. She felt better already. It really was all in how you looked at it, wasn’t it? Alright then. She looked down the path ahead of her, trying to remember whether she’d been in this particular part of Tartarus before.

“Princess?”

Everything froze. Again.

Celestia turned, slowly and agonizingly, toward the source of the sound. She saw, standing there, her worst nightmare.

Twilight Sparkle halted where she was, wings half up, worry written all over her face.

“Are you okay, Princess?”

Alright. I am in Tartarus right now with somepony for whom death is permanent and that is okay and I Am Not. Panicking. Right. Now.