The tap of a porcelain cup on serving platter was something almost completely foreign to Twilight. Well, not the sound itself, more of who made it. Celestia only narrowly avoided fumbling the ivory vessel again, placing it down in her arcane grasp with an uneasy breath. It had been fifteen minutes of false starts and incomplete explanations from the solar diarch, each of which had wound up trailing off into sniffles or uncomfortable silence.

“So,” Twilight starts with the lingering warble of hesitance.

'Oh mare, this is awkward.'

“Uh," Twilight ventures softly, "any better?”

Instead of trembling lips and a whisper like last time, Celestia clears her throat and meets Twilight's gaze. There's no words, but Celestia does manage a quick nod.

Celestia tucks her wings against her side and stiffens her spine to gather some degree of composure. “Thank you for the tea, Twilight.”

Then lapses back into deafening silence.

It wasn't her patience failing, Twilight almost sensed herself sliding into the same pit of despair that Celestia had. It wasn't just empathy for her friend and mentor, the cloying air around her was palpable. Although, she did feel pity and a sense of awkwardness as Celestia's eyes dip to take in the tabletop.

“Princess," Twilight licks her suddenly parched lips, "I have to ask, why exactly am I here?”

“Why are you here, Lu...” the rising heat of indignation is quenched the moment Celestia's eyes met her own. “Twilight... I'm sorry.”

Again, silence, but this time an almost companionable one. Celestia's feathers ruffle as a scrunch slides across her muzzle. A sip of tea and deep breath steadies her voice. “As you've no doubt guessed, it's Luna.”

Pausing only long enough for Twilight to nod her confirmation, the diarch continues. “Last night my sister had an… episode.” The word evidently curdles on her tongue as she spat it out with disgust. It didn't escape Twilight's notice, the smaller Alicorn could have tried to read something into it, but Celestia's practiced stoicism had since returned in full force. “Her maids found her delving through the library, researching something. She confided in me that the Nightmare had returned.”

“But the elements-” Twilight's interjection is smothered by Celestia's raised hoof.

“Yes, Twilight. The Elements banished the Nightmare from my sister and returned her to the pony she was before.” Celestia's quickly rattled off response held all the air of a practiced speech, but it was the lifted hoof that halts Twilight’s nascent protest, “She said this was different, it tried to taunt her rather than appeal to her. She was... manic. She ignored her maids and chased the guards out of her study. That's when they asked me to see to her. I normally don't interfere with her responsibilities, but they were insistent." A sigh passes her lips and she steadies herself with another sip of the soft amber liquid.

A thousand questions and as many summations pass through Twilight's mind: 'who, what, when', and most notably 'how'. She fidgets, ears waggling in thought. And just as she tries to form a question, Celestia continues. “It concerned her. I could see it. She insisted she wasn't sick, she wasn't overly stressed, but I could see she was troubled. She insisted that this Nightmare drove her from the dream realm.”

'Drove her... what? She's the Princess of dreams, how is that even possible?!'

The whole thing was bizarre. Something being able to drive Luna out of a dreamscape was unfathomable. Celestia's voice snaps her out of the stream of thoughts. “And something else tried to speak to her. She said this thing wasn't a Nightmare but made of something like it and a dreamer. I just... I tried to say that I could help, or that I would ask you on her behalf, but she insisted on being the pony to ask for help. Well, you know Luna. She's a stubborn pony, so I let it go. But a few hours later I was summoned to the kitchen and...” Celestia's voice trails off into obscurity and tries to return to the calming presence of the tea.

The solar diarch continues after willing her voice back to a more sedate tone. “The Physicians say that she may have just fallen asleep, struck her head and is suffering from a concussion. But she's not waking up. They've tried balms, spells, herbal poultices, everything that can be done. Starswirl is on his way from the Glory Hooves mountains and I have more physicians including several from the crystal empire who should be arriving tomorrow.”

And despite that, Twilight blinks back confusion. “So why would you need- you think this is all because of the Nightmare, not an injury, right?”

It's confirmed in a simple nod, but the pleading glance through shimmering eyes brimming with a fresh wave of tears was enough to convince Twilight. Taking her cup, she drains everything left in it and swills the dregs in her mouth, tasting the slight bitterness. “ I'd like to think I've got a basic understanding of Thaumatalogical medicine but... I may need some help. I'll help in any way I can. But, maybe it would be best to wait? I mean, Starswirl alone probably has forgotten more than I know about it.”

“Twilight," Celestia's hoof stretches across the table and gently rests atop her own. It was soft, certain, everything her tone hadn't been just minutes before. "You know my sister as well as Starswirl ever did. She trusts you, and I trust you. I know it might be exactly what the physicians suspect. But, if it's not, I trust you to find a way to help my sister.” She fixes her gaze on the younger Alicorn and smiles hopefully, “Please.”

It was Celestia asking, and Twilight could only nod, words springing to her mouth unbidden. “Of course, Princess. Anything.”

'Well... I did say anything.'

The first steps of Twilight's plan was the same as any other research project: acquire information.

With the royal archives so close, she'd once more settled back into her study nest and awaited reports, documents, and suppositions from the medical staff. The affidavits, or more accurately, 'half-remembered and terrified recollections' of the kitchen staff that called for Celestia were already categorized and tucked into a folio.

Four candelabras and several arcane lumin orbs cast pale amber light over the scene of scholastic chaos. Open scrolls and heaps of medical textbooks lay around the Alicorn in a pattern so similar to the sun that it could have been mistaken for a convoluted solar summoning circle. Twilights desk stayed a relative island of peace among the apparent mayhem. There's just a single sheet of paper, inkwell, and three tomes laid open to a series of referential charts marked with white linen strips.

Hours has passed, but something was emerging.

"It's just a matter of seeing the pat-"

A knock sounds on the door. Twilight turns just as a familiar lab coated pony peeps inside. “Princess Sparkle?”

Twilight glances up, catching the periwinkle Unicorn mare with short Lemon-yellow locks and a veritable filing cabinet's worth of papers stuffed in her overladen saddle bags.

“Doctor Barnyard, please, come in.” Twilight waves the medical mare inside and gestures towards a maroon crushed velvet cushion just outside her immediate study circle. “Have the test results come in yet?”

“Yes.” Doctor Barnyard gingerly watches her step, careful to avoid the carpet of papers that had been crumpled and discarded. They lay in a heap, partially obscuring the intricate needlework of the Saddle Arabian rug. The Unicorn mare takes a seat, fishing out a series of files from her pannier.

The bags swiftly flicker from Barnyard's teal magical aura to Twilight's bright raspberry. The files are open and parsed out as soon as they leave the doctor's grip. “Hmmph, you're welcome.” She mutters mostly under her breath, but Twilight's ears pivot towards her to show it was heard.

Blushing faintly, the doctor clears her throat and begins in a more professional mien. “As you can see with her urology and toxicology results, the patient is well within the parameters of a normal healthy individual of her genotype. Magical resonance imaging results have also come back as normal.”

“So, for an Alicorn, she's fine.” Twilight mutters absently. The Alicorn flips through the indicated reports, glancing down the page of terms and abbreviations that she'd had to familiarize herself with just hours before. It only takes a quick glance to a scribbled page of medical terminology to cross-referenced what Barnyard was saying. “She wasn't poisoned, there's no toxins, it's not an infection, and the MRI hasn't picked up any other physical problems.”

All of which were affirmed by Barnyard's nod. A pair of tiny wire-framed spectacles levitates out of the doctor's breast pocket and drifts to her muzzle.
“Exactly. But look at the hematology result.”

“Is there a reason I need to see bloodwork before thaumatology?”

With a faint blush again, the doctor squirms in her seat and nods. “Uh-yes, exactly. Look at some of the numbers for hormone levels.”

'Oh... oh, please don't say she's pregna- woah.'

Twilight's voice creeps higher, turning a little more shrill, “W-why is her cortisol levels spiking? Her blood pressure is high. Extremely high.”

'Fight or flight response, adrenal secretion responses. Okay, so, coma patients are supposed to be at rest. Luna's not.... so it's not a medical coma. Wait, is this what a Nightmare incident looks like?'

Despite the doctor casting a sideways glance at the Alicorn, she gives her a little nod as non-verbal permission to continue to the next file folio.

Twilight glances over the far more familiar field that was the study of magic. “Her thaumotology readings are literally off the chart. There's intersecting active waves, cycling patterning and interference results, haptic feedback.... wait, she's having seizures from magic feedback?”

The Alicorn didn't look up for clarification, but confirmation as her eyes widen with a dawning realization.

“She's channeling and somehow using enough magic that I'd be concerned she's trying to kill the sky. And forgive me, Princess Sparkle, but I've been a medical researcher for more than fifty moons and I have seen the medical information of every princess. For science, I assure you. But this is unprecedented in a single individual, it's far closer to the-”

“Elements of harmony.” Twilight interrupts.

With a snort, Barnyard mutters, “We don't have numbers for that, and the field of study is hardly exhaustive. So I thought it more appropriate to use some of the readings recorded from Princess Cadenza's royal wedding incident as a benchmark.”

Twilight looks the numbers over again, and swiftly shuts more than half a dozen tomes before dragging twice as many books over in a rotating circle around her head. “Thank you, doctor. I may have to call on you again soon. But for now it might be best to take a break and get some rest.”

“Your majesty-”

“Please," the Princess flashes a practiced grin meant to be disarming, "just Twilight.”

“Alright. Twilight. I have files on all of the princesses. That includes yourself, of course. Forgive me for saying, but you're about the last pony that should be telling others to 'take a break and get some rest'. We are all professionals and handling this as well as... can be... expected.” The slow, awkward, meandering phrasing finally stops cold when the doctor realizes Twilight had stopped paying attention.

“Ahah!” The Alicorn was already up and moving by the time the doctor's hackles had smoothed back down. “I'll get Pernhurst's Compendium to Mystical and Magical Maladies, and Afflictions ex Infurium in the original Old Ponish, as well as Malestare Crawly’s Message of the Magister Thestrals on Umbral Shadows and Ushering in the Next Aeon! And I know just the pony that can help!"

Twilight flutters around amid a flurry of loose papers and tottering book towers in the appropriated quarters. Even as she shoves papers and folios in her saddle bags, her brisk trot and manic bounce erases all the tiredness of the morning. Collecting her supplies and donning a short magister's robe left out to ward off the rain, she hastily makes her way out the door.

“.. okay, I'll just be in the staff room...” Doctor Barnyard awkwardly looks to and fro as Twilight snuffs the candelebras and douses the arcane light, leaving one confused Unicorn sitting in the dark. With a subtle 'floomph' a slide of scrolls tumbles to the floor. "...Princesses."

The incessant rapping at the front door never slowed, let alone ceased.

“Alright, alright! Calm your teats, I'm coming!” a terse and relatively sharp feminine voice calls from the other side as the lock slides back.

Twilight flares her nostrils and quickly charges her horn. With a noisy crack-pop, the Alicorn swiftly teleports herself from the rainy Canterlot street to the other side of the rickety oak door just as it creaks open.

A cream coated mare stares out on the now vacant Canterlot street corner. Spray from a passing carriage blows in, misting the mare's wide glasses and forming droplets on her scarlet streaked mane. The black scrunchy holding up her bangs soaks in even more, leaving a noticeable rivulet tracing down the spiral of her horn.

“Alright, we have a hundred things to do, Moondancer. The area's already isolated and most of the books and volumes we need are there, but I brought a few myself to see what you think. I figured it would be best if we did a thorough examination, test things ourselves and start fresh. With any luck, we should get it done by this evening and the results back before midnight. The fate of Equestria may be at stake here! Now, do you still have that old complete works of Malestare Crawly?”

The door slams shut, the mare still staring at the back of it for a moment before taking in a deep steadying breath as Twilight's trots from the foyer into the dusty inner sanctum. The mare tries to wipe her glasses off on her still wet sweater, streaking the lenses and drawing out a shaky huff of mounting irritation. “Morning Twilight, how nice of you to send me a letter that you were in town and planned on dropping in."

The only response is Twilight's receding hoofsteps.

“Princesses.”

“Ummm...yep, that's an Alicorn. So, uh, why am I here?”

Twilight's intense glare at Moondancer's flippant muttering does little but get the Unicorn to push her glasses further up her snout. Moondancer patently ignores her in favour of straightening the castle visitor pass looped on a lanyard around her neck. The Unicorn could hardly be bothered as she sweeps her bangs from her face, only for the curtain of hair to bob right back in front of her glasses. She shrugs her pack off and nudges it into the corner.

Her own voice comes out far softer, respectful and perhaps a little numb. "They may have overlooked something."

She turns her attention back to the shrouded form of the dark Alicorn laying on the small medical cot. It still cut a strange sight, one of the regal princesses laying in a tiny bed covered in a lush royal duvet. It was folded twice over yet still draping down to the ground like a star-spangled waterfall. The rest of the room was positively mundane, and the steady series of blips of medical equipment was all there was to distract from the stink of antiseptic clinging to every surface. The walls were bare except for a few Equestrian Health Network posters asking patients to wash their hooves thoroughly.

Twilight catches the image of Moondancer trying to rub her glasses clean on her smudged sweater from the reflection of a glass cabinet. Disposable medical supplies lined the shelves, but the simple granite desk for charts and papers were now crowded with the research books, notes, and writing supplies she had brought. “Look, Twilight, they were professional doctors. This isn't like a one-cart town herbalist down in Hayseed Swamp. They have, you know, degrees. Certificates. Brass plaques with their names on them.”

Part of Twilight knew that her friend was right, they hadn't just elected to miss something that she, in all her amateur knowledge, would discover. But it just felt like she was doing something, at least being there in case whatever it was that could happen, happened. Twilight takes a few steps closer to Luna, silent while her friend meandered off on her own train of thought. She reaches a hoof out to brush against Luna's blanket covered barrel.

'Cold but still sweating.'

The Princess's heart raced as sweat bleeds into the thin sheet. Her body seemed to be trying to shed warmth despite her being clammy to the touch. From that to the little droplets of moisture along the Alicorn's horn, the medical files had been so perfectly impersonal. But being right next to her, seeing the little microspasms, rippling shivers and raised hackles, it was unsettling.

A pit forms in Twilight's stomach: perhaps there was nothing she could do except for, maybe, just being there.

'No, no that's not like you, Twilight!'

With a quick shake of her head, she gathers the blanket up and pulls it further up Luna's body.

“-and finish the prelim notes over a hot trotty. Your treat, because you dragged me away from my studies and all. It's only fair, right? So, can we get out of here?” Moondancer nods expectantly.

Somehow, Twilight had missed the start of her friends apparent rant. Although the idea of a drink was a good one when they were done, they'd barely started. “Sorry, Moondancer. We can't just go yet.”

Moondancer's snort draws Twilight's attention again. Looking back to see the slightly furrowed brow and pinched muzzle, something still felt a little off.

Twilight pensively hums and glances around the spartan room, “We need to look through all of this, did you read all of the medical report?”

“Of course. I had to do something on the way here.” Moondancer sniffs and tilts her head upward, glancing at the few pedestrian posters tacked up on the walls. A suspicion forms in Twilight as Moondancer turns her gaze to the disposable tongue depressors in a jar.

'She's not even looking, is she?'

Twilight canters over to her friend. “Moondancer, you're one of the smartest ponies I know. Please,” she reaching out to brush her hoof over the mare's withers, “help me, help Luna.”

Moondancer finally turns her attention to Twilight, and with a slight shift and gesture, she's redirected to the unresponsive Alicorn. The Unicorn's lower lip trembles for a moment as her voice dips to near inaudibility. “O-okay.”

Twilight cocks her head to the side, staring at Moondancer, forming words on her lips but staying silent. Instead, she tosses a hoof over her withers and sidles up side-to-side before finally adding, “Between us, I'm sure we can figure out what's wrong.”

Moondancer nods silently in reply. Trotting over to her notes, the Unicorn nervously licks her lips, keeping her gaze downcast towards the missives. She pulls free a sheaf and raises her voice a little louder than strictly necessary. “Okay, so, I had a thought about that. A lot of these symptoms are incongruous. It's not toxins, it's not a sickness, it's not physical injury. Right?”

“Right.” Twilight seizes on the sudden mood shift.

“So," Moondancer continues, "I was thinking, if it's not any of those, what else could it be?”

Twilight nods and glances over at Luna. She shivers and twitches, but nothing else, head tucked down against her neck like a curled up bird.

"We should consider that it's not inherently physical in nature. But first-” Letting her own sentence peter out, Moondancer turns to root through her pack. The flaps pop open as she digs through, shifting what sounded like glass and metal around before fetching a neat featherless quill. Placing it aside with a tiny vile of ink, Moondancer drags out a plain platinum rod in her telekenetic grasp. A coiled cord trails down to a meter box with a few adjustable knobs and glass-faced displays. A thaumatology meter.

“Here, hold this.” Moondancer mutters, passing Twilight the meter reader. The Alicorn takes a hold of it, cradling it in her hooves. She knew the procedure. It was an aged, well used, and yet surprisingly heavy device that had seen better days, as evident by the hastily repaired back panel.

Twilight blinks and takes a look at the calibration.

'100 Thaumins!?'

A hundred times the magical potential output of a typical unstressed Unicorn. In Moondancer's arcane grasp, the needle barely moved. It was certainly under 5, probably in the lower half. “What are you doing with an industrial grade thaumometer? Besides, I know this sounds like a good idea, but we already know-”

“Shhhhh.” Moondancer quiets her sharply. “Aren't you always saying we should double check the results?”

Twilight is gently brushed aside as Moondancer trots over to Luna. The guards on the other side of the door would no-doubt have a fit, but Moondancer's inner researcher seemed to have finally taken hold. A little head bob brings Twilight to her side. The lavender Alicorn watches the meter as Moondancer gently presses the rod to Luna's horn. Even before she had made contact, the dial needle shoots up and taps the metal pin past 100.

It wasn't exactly a surprise, but the sound the meter made as it tapped was a little jarring. Twilight takes a breath, lapsing back into her studied mien, “Well we know that Luna has a resting potential of about a hundred and twenty. So, while we know that she isn't- what are you doing?”

Twilight yelps as the meter is snatched from her hooves. She bats at it, trying to catch the device by instinct as it's held in Moondancer's lilac arcane field. With a rusty creak, the back plate pops out and clatters to the floor.

“Hold this,” The Unicorn lazily tosses the rod to Twilight. Caught by instinct, the platinum rod levitates in Twilight's lavender arcane grasp. The meter's pin spikes for a moment, tapping the 100 as Twilight clenches the rod, but it settles back down to 73 with a few little wobbles.

A dawning realization creeps over the Alicorn's face. “Wait, you're using me as a magical load to create a tear yield?”

“Precisely. More power, lets get it up to at least eighty.” Moondancer quickly nods despite a deadpan look from Twilight. The Unicorn blinks and just shrugs, “It's easily hoof dividable and it's the principle that counts. Trust me, it's better this way.”

With a bit of magical effort, Twilight mumbles, “Parrato principle, maybe.”

“Hold it there!” Moondancer replies and quickly turns the back of the meter, grasping a tongue depressor and quickly using it to unscrew something. With another twist and a quick check on the front, she smiles and nods. “ Alright, tear is at eighty RPTE. Lets try this again.”

Twilight nods and they retry their test, the meter in her grasp and Moondancer resting the platinum rod to Luna's horn. And again, the meter needle shoots up with a click, tapping past the 100 in the blink of an eye.

“Ish dat o'r un-eighey?” Speaking around the rod in her mouth, Moondancer glances back over her shoulder before spitting it out and catching it with her own magic.

“Yeah," Twilight stares at the unmoving dial restrained by the simple silver pin. "Way over one-eighty. You know what this means?”

Moondancer nods, “That she's actively stressed and using magic. How much, well, we don't have firm numbers for her anyway so we can only guess.”

A quick glance back at the dark Alicorn quickly turns into a stare. Twilight bites her lip and asks aloud, “do you think that her state is from magic exhaustion?”

“It's looking like that. But magic should just drop back to its resting potential when a Unicorn falls unconscious. Maybe it's different for an Alicorn?”

Looking to Twilight for confirmation only draws a quick shake of her head. “No, no it's still the same. We're still just ponies. Essentially.”

“Twilight,” Moondancer's tone slips into something icy and quiet. “I have a theory, and I don't like it.”

Seeing that there was no response from Twilight, Moondancer pensively nibbles her cheek and begins. “Princess Luna is under strain, so, maybe it's from some magical attack? Her body is exhibiting physiological responses to stress, not sickness or injury. If she's in a coma, it avoids outside stimulation so the magical energy won't fluctuate due to distraction. So, maybe she's like this because she chooses to be?”

"Well," Twilight mulls over what she knew aloud. "Celestia did mention that Luna said there was a Nightmare that drove her out of the dreamscape and something else tried to talk with her. Do you think that's what this could be?"

Deathly, piercing, incomfortable silence greet's Twilight's reply. Moondancer's eyes widen and a twitch creeps up the side of her face. "...what."

Twilight's mind races, hoping for something to refute the concept, to point to an alternative, and yet it was ticking quite a number of mental boxes. "I didn't mention that? Hmm, I guess it might not be in the reports."

Moondancer rubs a hoof to her eyes, shoving her glasses up and over the intruding forelimb. The laugh that bubbles from her throat was mirthless and cold.

Seeing no response, Twilight let her train of thought continue uninterrupted. "Magic is just being used, but we don't know how or why. Still, it has to be affecting something. Simple first law of thaumodynamics. So, we need a way in.” Twilight spoke, not realizing the flat and scholastic tone she had adapted. Luna needed help, and this was a new hypothetical that was coming close to confirmed. Even Moondancer's slightly surprised expression barely registers as Twilight mulls her thoughts over.

"Twilight," the Unicorn says, shooting her an unamused glare. Is there anything else that I should probably know? We're not going to have to venture to Mount Dread to find some magic Alicorn ring that Celestia told you about, or assemble the Justice League of Equestria, right?"

"Hmm, but who else knows dream magic?" Twilight continues, lost in thought and mumbling more to herself by then. Her eyes flit between the Equestrian Health Network and the Alicorn. "Luna mentioned that Celestia wasn't adept at dream magic when we dealt with the Tantabus." Moondancer was saying something that bled into the background hum of the overhead lights. "Hmm, Starlight knows, and a few at the university must have an idea. But they might not know how to create a shared space. If only we knew what we were up against, we might be able to figure out what we need to do. Meaning that if we can get a glimpse of what's going on, maybe-”

A flash of inspiration hits her like a runaway cart.

'An empath. An empath might be able to find out even if she's not awake.'

Moondancer's reply flits off, it takes a faint arcane snap and burst of magic in front of her eyes to get Twilight conscious of the sour, frustrated face just a hooflength away.

“-And furthermore, if we're going to be research partners then we both have to pay attention. If this is about the earlier-”

Twilight bolts up and snatches a quill and ink from the academic heap on the desk. “M-hmm, I'm listening, just gotta write this. Just give me a second.”

Her hoofwriting was messy and remarkably swift, and even as Twilight spun to her hooves and gallops to the door, the parchment was being shaken in the air to dry.

“Write what?” Moondancer calls after her. She was slower on her hooves, and the sound of a rustling bag and clinking equipment says she's collecting her accouterments before following along.

“Don't worry, I'll be right back!" By now, Twilight was shouting as she barrels past the two guards posted outside the door and leaving Moondancer to awkwardly step past them. "I just have to send this letter back to Spike and hope Starlight's not already on the train. I need her to pick up a book for me.” The Unicorn follows after but almost immediately is out of sight as Twilight turns a corner of the stairwell, heading upwards.

The Unicorn's voice reaches her, even if at a distance. “Why would Starlight already be on a train?!”

“Because I wrote her to come here as fast as she could before I left for your pla.... uh...”

“TWILIGHT!”

“I'm sorry!”