Ponyville, October 9
10:46 PM — 2 hours after the Fracture in Time

Starlight and Sunburst got lucky. Monarch wasn’t watching Sunburst’s rented apartment or the trains, and after picking up all of his notes that they could, they managed to grab a late, late train to Ponyville. By the time they’d reached Ponyville, it was long past dark and the two of them had to light their horns to find their way.

“Are you sure this is a good idea?” asked Sunburst as they walked down the street. He ran a hoof through his mane. “I’ve never heard of this… what’s his name again? Doctor… Who?”

“No, Whooves. Doctor Whooves.”

Sunburst cocked his head in thought for a moment, then shook his head. “Nope. Doesn’t ring a, ring a bell.”

“Doctor Time Turner Whooves?”

“…Nope, still noth-” Time stopped for a second and Starlight’s brain skipped a beat. “-ing.” Sunburst frowned at Starlight. “You, you’ve got that look. Stutter?”

Starlight sighed and rubbed her forehead. “Yeah. It’s not going to get better, is it?” Time had stuttered twice during the train ride back, and she was finding it hard to adjust to.

“Not unless we can fix time.”

The absurdity of that statement was inversely proportional to what Starlight thought was the likelihood of them actually doing it.

Starlight led them to a blue, somewhat boxy house on the edge of town. Surprisingly, behind the drawn curtains in the window, the lights were on. Sunburst mashed his muzzle up against the glass, trying to squint through the gap in the curtain. “Is he always up this late?”

“Not as far as I know,” Starlight said. Knocking on the door, she said, “Hey! Doc?” She didn’t yell yet; she didn’t want to wake up anypony else.

“Be with you in just a moment!” the Doctor hollered back. “I’ve got- Never mind, right there!” A few seconds later, a very tired-looking Doctor yanked the door open. His mane was rumpled and he wasn’t standing as tall as he could’ve been. “Apologies,” he muttered, “but one of my inventions started going haywire a few hours ago, and I can’t for the life of me figure out what’s going on. Anyway…” He took a deep breath and straightened his legs. “How can I help you, Starlight and, uh…” He lowered an ear and frowned at Sunburst.

Sunburst half-grinned awkwardly. “I’m, uh, I’m Sunburst,” he said quietly, “and I’m a friend of Starlight’s, and we broke time, and we might need your help to fix it.”

The Doctor blinked. “I think we might need some tea.”

Several minutes later, the trio was ensconced in the Doctor’s lab with some tea. Starlight remained silent as Sunburst explained what he could and the Doctor pored over Sunburst’s notes. “…s-so, um, I think the Neigher-Joy field is breaking down,” said Sunburst, “and time’s stuttering, and it’s going to end if we don’t, um, do something about it. Yyyyyyeah.”

To his credit, the Doctor took it much better than Starlight. No “wait, what?”s going on. “Yes, that is… a rather severe problem,” he said. “Give a moment, and I’ll be done with-”

Then he frowned. “Hang on. These…” He began flipping through the pages, taking a quick look at each one. “Hang on hang on haaaaaang ooooooooon…” He went silent for a moment as he stared a page. “These are my equations.”

“Wait, what?” Sunburst said, sitting up straight and pushing up his glasses. “You mea-”

“I don’t mean plagiarized,” said the Doctor. He started scanning each and every sheet of paper. “I mean, I came up with these eight years ago. Some of the derivations are different and they use different letters for the variables, but…” He ran his hoof down a particularly complex set of equations, his lips moving soundlessly. “Yes, I had these exact equations eight years ago. I-”

He flicked to another sheet and examined it. When he spoke again, he sounded both outraged and ecstatic. “I had these models down pat! That hadn’t been a mistake, I was right all along!”

Starlight and Sunburst looked at each other. “What do you mean, you were right?” asked Starlight.

“Long story,” said the Doctor, “but I was developing my own theory of this when I thought I found an early mistake that invalidated everything. From the looks of things, my model was essentially identical to yours. Although I called the particles…” He cringed and his voice dropped to a whisper. “…timeons.”

Starlight and Sunburst both blinked. Sunburst coughed, and Starlight said, “Just when I thought you couldn’t get dorkier than ‘chronons’…”

“But but buuuuuuut…” muttered the Doctor, “that means…” He darted over to a table and picked up a strange device that looked like a tape recorder with a hose attached. “If I was right,” he said, pulling it back over to Starlight and Sunburst, “then this should be work, and I sho-”

Time chose that moment to stutter. Once it started up again, the thing suddenly let out an earsplitting ringing sound; everypony jumped and clamped their hooves over their ears. Eventually, it stopped, and the Doctor groaned. “Gah. Apologies. It’s been doing that at random for hours, now, and-”

“Time just froze for a second,” interrupted Starlight. “Those stutters Sunburst was talking about.”

“We don’t know when they come,” said Sunburst. “They just happen.”

The Doctor barely seemed to be listening. “So… this is working properly, it’s time that isn’t!” He grinned. He stopped when he saw Starlight’s and Sunburst’s mortified looks and coughed. “Although, ah, that’s not… very good, is it? Ah, no.” He looked at the hose and pursed his lips. “Let me try something for a quick second.”

Before either Starlight or Sunburst could say anything, the Doctor had picked up the end of the hose in his teeth. He pointed it at himself. Nothing. “Ah-hah.” He pointed the hose at Sunburst. The device started making small, sporadic dinging noises. “Ah-hah.” He pointed it at Starlight. The device started dinging like a downpour of hail on a metal roof. “Ah-haaaaaah…”

Starlight wasn’t sure why, but she took a few steps back. “Uh… just what does that do? Why’s it dinging?”

The Doctor grinned, let the hose drop, and propped the device up with a hoof. “This is my own invention, the Timelike Anomaly, Resonance, Disruption, and Interference Sensor. It detects non-background production or density of chronons, symptomatic of time travel — point of fact, magical or scientific — or other forms of mucking about with time, and stutters would naturally have all sorts of messy chronon production that I haven’t calibrated for.”

Starlight blinked and coughed. “Equestrian, please?”

“This is my timey-wimey detector. It goes ding when there’s stuff.” The Doctor looked down at the dinging-like-mad timey-wimey detector and frowned. “And great whickering stallions, do you have a lot of stuff. What in Celestia’s name happened to you?”

“Serene was in the machine when it broke, and I was trying to get her out. I was right at the door.”

The Doctor bit his lip, nudged the hose of the timey-wimey detector away from Starlight, and flipped back a few pages to a rough diagram of the time machine. “So you were within…” He traced his hoof along a line. “…thirty feet or so of the core, yes?”

“I think so, yeah.”

“Then I have at least an inkling of what happened,” said the Doctor, looking up at her. “Your proximity to the core at the moment of fracturing resulted in an extreme dosage of chronon radiation, effectively separating your Neigher-Joy field from the rest of the world’s.”

Starlight blinked.

“Your timeline’s all wibbly-wobbly relative to the world’s.” He tapped his chin for a moment. “How can I… Ah, got it! Be back in just a moment!” He raced into the kitchen.

Sunburst coughed. “Is he, um, always like this?”

“Pretty much, yeah.”

The Doctor walked back in, balancing three cups on his back, one of which was full of water. He quickly brushed a bunch of fragile-looking things off of a table and set the cups down on it. “Right! So,” he said, rubbing his hooves together, “pretend water flow represents the chronon emission/absorption rate. It’s actually nothing like that, but pretend it’s like that.”

Already a bit lost, Starlight opened her mouth, but the Doctor quickly waved her down. “It’ll make more sense in a second, bear with me. Normally, time flows at the same rate for everything, because everything’s getting the same chronons.” He worked his hoof into the handle in the water cup and poured it into one of the empty ones. “You, however, received such an excess of chronons that you effectively are outside.” He poured the water into an empty cup again, but this time, he moved the other empty cup halfway under the stream, splitting the water half and half between the two cups. Setting the half-full cups next to each other, the Doctor tapped them once each. “This is the universal Neigher-Joy field. And this is you. Two entirely separate sources of chronons.”

Sunburst looked satisfied, but Starlight just nodded slowly. She kind of got it, but didn’t want to say so in case the Doctor wanted to keep going and she’d start floundering under all the information.

The Doctor being the Doctor, he kept going anyway. “Of course, that would also imply- Hang on hang on haaaang oooon…” He frowned. “Are you still active within these stutters? You still move while everything’s frozen?”

Starlight twitched. “Y-yeah, actually. How’d you know that?”

“Quite simple, really. Separated from the Neigher-Joy field, you run on an entirely separate supply of chronons, the one you received from the fracture. Basically, you’re on your own timeline, completely distinct from this one, that just happens to intersect with it. When time in the world at large stops due to a halt in chronon production, the chronons you’ve stored up allow you to keep moving. Hypothetically, you could dose a, quote-unquote-” The Doctor even air quotes. “-‘normal’ pony with your chronons to allow them to keep moving as well.”

“I’ve, um, actually already done that,” said Starlight. “During a few stutters, I’ve unfrozen Sunburst.”

The Doctor boggled. “Really? Already? Fascinating! I suppose, being a unicorn, manipulating chronons might not be that dissimilar from manipulating magic.”

Sunburst sat up straight. “Hang on. If, if she’s not on ‘our’ time, then why’s she still, still moving through time? She’s not absorbing chronons, is she?”

“Correct,” the Doctor said with a nod. “As of right now, Starlight is no longer passively absorbing chronons from the Neigher-Joy field, and her passage through time is dependent on what limited supply she absorbed from the fracture. Based on these numbers, I’m guessing she has a decade of time left.”

More technobabble that flew over Starlight’s head. But not Sunburst’s. “That sounds bad,” he said.

The Doctor kept rambling, like he hadn’t heard Sunburst. “But you can replenish them in a variety of ways. Say, actively absorbing them from the environment, although that would cause time to temporarily stop within the affected region. And your free manipulation of chronons would allow all sorts of nifty abilities due to differing time rates between yourself and the world.”

Starlight cocked her head. “That… doesn’t sound that bad, actually.”

“But if you did run out of chronons, you would decohere across spacetime and be unable to exist at any individual point, in any given instant, in any given timeline.”

“Scratch that.”

“Although…” The Doctor looked up and tapped his chin. “Hypothetically speaking, if you weren’t driven to insanity by such a hellish existence, you might be able to draw yourself back together and, separated from the Neigher-Joy field, become omnipotent well beyond even Discord’s stature, since you would exist in all places, at all times, in all timelines, and-”

“Considering it’d require me to get splattered across the history of the universe first, I’ll pass, thanks.”

“Apologies. The Neigher-Joy field and its implications are just so fascinating.”

Sunburst cleared his throat and pushed his glasses up his muzzle. “Speaking of, um, of implications, does this mean you can help us? It’s kind of, uh, important that we fix the Neigher-Joy field.”

The Doctor sucked in a breath through gritted teeth. “That I’m not sure of. Maybe, but I’d need some time to be certain of that, and it would be extremely complicated. It’d probably just be simpler to go back before you started the machine and stop whoever broke it.”

“Can’t do that,” said Sunburst quickly. “Paradoxes cause destructive interference within the Neigher-Joy field that get pushed away. They are, at best, purely hypothetical.”

“McFlier cascades are supposed to be hypothetical, too, you know.”

Sunburst twitched, looked away, and folded his ears back. “But we ran the numbers,” he muttered. “Paradoxes can’t happen.”

“I won’t say my running of the numbers confirmed paradoxes,” said the Doctor, “-or should that be paradoces?- but I never saw anything that explicitly disproved them, either.” He tapped his chin. “Then again, I never got as far as you did…”

Starlight wanted to chime in with her own experience with “paradoxes”. But the Doctor didn’t know of her past experience with time travel, and she wasn’t sure she was comfortable telling him just yet. The situation wasn’t that desperate. Yet. She held her tongue.

“Well, one way or another,” said Sunburst, “going back at all, that’s, that isn’t happening. Unless you happen to, to have an old time machine lying around,” he added sarcastically.

“If these equations are correct,” the Doctor said, “I think I do.”

Sunburst blinked. “…OH, COME ON!”