"Something has happened to time."

You'd think I could word that a bit more floridly. Maybe launch into a big, complicated explanation of what exactly has happened, not even trying to swap the big words out for the bite-size vocabulary that this scienceless sphere has to contend with. And, well, I could, but it feels too big for that. It's one of those rare times when something's so big, I have to use small words.

"That's the twenty-seventh time this week, Doc. You sure you ain't got any big speeches for this one?"

Plus, she'll just end up correcting me if I use a word wrong.

"There's hardly enough words in this language, my friend. I've never seen such an enormous temporal shift."

For once, we aren't in the laboratory. I never thought I'd miss all those crude mechanisms of timber and glass, but studying the effects of temporal distortion on the TARDIS console... it feels like I'm cheating somehow.

Maybe it's because the console isn't designed for hooves. Yeah. That must be it.

"So, is this like that thing with the butterflies?" Normally, I'd sneer and crack a joke about Danaus plexippus, but this mare doesn't hang around because of cuteness and variety. She's pulled up a picture of the Lorenz system on the other screen, bless her single heart.

"Precisely, Derpy. This is proof positive of the butterfly effect if ever there was any. The simplest of changes enacted upon an event in the past have had disastrous consequences that lead directly into the present. To wit, this 'Crystal War' business that everypony's going on about."

I switch over to the chronometric analysis feed, and easily anticipate her next question. "So, what happened that put Sombra back on top? Did Cadence forget to drink her coffee? Did Twilight go it alone? Did one of the Elements die of pneumonia?"

The numbers dance before my eyes, but the answer to the equation is quick to distract from the symphony. "Seems it's less a case of what  happened, and more a case of what didn't happen." I flick a lever and push a button, swapping the image of the Lorenz system out for a temporal replay. "Recognize anything?"

A bright smile of recollection all but spontaneously manifests on her face. "That's Rainbow's first Sonic Rainboom!"

I nod, and smile wistfully at the screen. This is one of the most important events in recent history;  the day that created Eqeustria's greatest heroes, the Bearers of Harmony. It's a focal point of so many diverging timelines that I can see the telltale flicker of at least fifteen perception filters in the replay. In all of time and space, I know only one other place that I've visited so often, but even that doesn't compare to this single explosive moment. To a Time Lord, that rainboom is a more beautiful and terrifying sight than the Untempered Schism. I've felt its echoes, both figuratively and literally, everywhere and everywhen I've been since I came to Equestria.

And now I know why I've felt sick to my stomach since we landed.

She sees it before I can draw attention to it. "Hey, is that Princess Twilight? What's she doing there? Wasn't she a filly back then? And a unicorn?" The smile becomes a frown, and then her jaw drops as it sinks in.

"Exactly." I let the replay move forward. Even though I know what's happened, I want to see it happen. There's the tragically necessary accident with Fluttershy, the first ring, the sharp corners, the brown one smashes into a column, and it all builds towards the glorious climax...

"There." My hooves all but slam into the console. The image freezes, magnifies, adjusts for clarity, and enters a loop. A single second replays over and over, showing a young Rainbow Dash freezing midair with the telltale glint of magic around her. Derpy points out a unicorn sitting on a cloud with a matching aura, and my breath catches in my throat. "Starlight Glimmer."

"What does she think she's doing?" Derpy's wings are fluttering faster now, a telltale hint of irritation. "Doesn't she know her country's history?"

"Evidently not." I dismiss the image in favor of the numbers. The equations say the same thing, but it feels... subdued, I suppose would be the word? I've always found the world much easier to understand when it's reduced to data on a screen.

"So, what's the plan, Doc?" She's started buzzing around like a hummingbird. "Are we going back to put the kibosh on this evil plan?"

"Princess Twilight beat us to the punch this time, Derpy. And we know better than most what happens when you have too many time travelers in one place."

"But it's Princess Twilight!" Her wings flare out and she snorts dismissively. "Who knows how much she'll have screwed up by the time she actually fixes anything! She'll probably end up overturning our entire system of government!"

"Quoth General Bright Eyes." I sigh, and propose another algorithm. The dance of numbers changes slightly, but not enough to give me hope. "She's hardly alone, Derpy. If you haven't noticed, the Master Tactician is right there beside her." That seems to stop her worrying.

"Okay, so what are we going to do?" Next Chapter: Rainbow Dash Joins the Ghost Wonderbolts Estimated time remaining: 20 Minutes