The Doctor sat in the TARDIS console room reading through multiple scans, his search was less for the culprit who was threatening Canterlot but more for a certain crack in reality and any signs of is (re)appearance.

"Why can't that chapter of my life just close... even here I must run from some segment of my previous actions it would seem."

The last time he had seen that crack was Trenzalore, the Time Lords planned to use it to return to the universe but ended up using it to grant him a new regeneration cycle.

"Could they be trying again? But if so that wouldn't explain why the crack appeared her and not where it's supposed to, and I really don't think this world is ready for a planet full of Time Lords straight out of the pits of hell that was the Time War."

*Dong*

The cloister bell rang out throughout the TARDIS.

"Hang on, what's wrong now?"

The Doctor was about to move from the display when a huge energy spike was recorded and appeared on screen.

"And what are you then?"

The Doctor tried to clear the signal and identify the energy, but it was gone just as quickly as it appeared.

*Dong*

The cloister bell still rang, something terrible had just happened.

The Doctor scanned again for any sign of the crack, any temporal anomalies that could be responsible for the crack or anything else out of the ordinary. Nothing. Everything seemed normal.

The Doctor shut off the cloister bell, he was worried. The scanner may not be able to detect anything but The Doctor already knew their mysterious culprit was making their move, it wouldn't be long before they would strike.

But not if The Doctor could help it.

All ten Ponies and a Dragon gathered in the castle throne room, it had been a quiet morning and the group had all shared breakfast together, all except for Twilight. When Celestia had inquired about Twilight's absence Spike had said how Twilight had been acting oddly smug about something or other the night before, and how that morning she had declined going to breakfast because she had 'stuff' to do.

Twilight however did eventually meet up with the group on the way to the throne room, while the group now stood almost in a circle discussing any possible place this threat may come from Twilight stood off to the side, watching.

"I checked in with my guard captain and yet he reports no unusual activity, the only abnormality on the streets is the air of uncertainty that surrounds our people due to the sudden appearance of the shield" Luna explained to the group.

"Did they check the caverns?"

"Tia my Lunar Guard have always been thorough, yes they checked the cavern. Nothing down there except broken mine equipment and a long dead bouquet of flowers."

"What about you Doctor? You certainly seem pensive about something," Celestia addressed the Time Lord.

The Doctor nodded, "Last night my ship seemed to... panic about something. Alongside the alarm I detected some sort of energy signature, but it disappeared before I could get a better read on it. After that all was normal."

"Could you tell what kind of magic it was at least?"

"I don't think it was magic..."

"Oh?"

"My TARDIS would never be worried about some random magic, it's temporal energies that worry her, the kind of thing usually associated with a paradox or a temporal disturbance.

"Her?" Applejack raised an eyebrow.

"Yes, her. Didn't I mention the TARDIS is a living sentient being."

"Say what now?"

"It's true!" Derpy interjected, "She's moved my bedroom more times than I can count..."

"Well we don't have much to go on..." Celestia started, "So we should start to come up with preemptive measures against any possible attack.

*Tap*, *Tap*, *Tap*, *Tap*

The Doctor moved into the centre of the group, "Right then! Since I'm the expert of temporal mechanics and am possibly, no actually definitely the smartest thing in this room might I make a few suggestions?"

Celestia seemed wholly bemused by The Doctors comment, Luna on the other hand snickered into her hoof.

*Tap*, *Tap*, *Tap*, *Tap*

"Well I think we should call in support from..."

*Tap*, *Tap*, *Tap*, *Tap*

Fluttershy heard the noise and turned to see it's source.

"Um... guys?" Fluttershy squeaked.

Nopony heard her.

"I think that..."

Everypony kept on talking strategy and temporal mechanics all giving idea's on how to protect Canterlot.

"Seriously I..."

Still nopony heard poor Fluttershy.

*BANG*, *BANG*, *BANG*, *BANG*

This got everypony's attention, and they all turned to see what was trying to get their attention.

It was Twilight.

"Twilight? What do you have to add?" Celestia asked her student slightly taken aback by the violent attention grab, the floor had been cracked where Twilight had stamped.

Twilight simply smiled and gave a small laugh.

"Twilight?"

"La la la, you so fine" Twilight said in a sing song voice.

"I beg you pardon?" Celestia was now a little confused by her former Protégé's actions, as were all the others.

"You blow my mind..."

The Doctors face darkened as cogs began to turn in his brain.

Twilight leaned forwards and sung in an almost whisper, "Hey Missy!".

The Doctor's world shattered.

"Oh..."

"Hey Missy! You so fine, you blow my mind! Hey MISSY!"

Twilight giggled before coughing lightly, "Sorry, got a bit carried away to the drum beats".

Twilight looked between the confused mares and dragon, and one horrified stallion.

"So..." Twilight smiled creepily, "Who wants to die first?"

...

Twilight's friends recoiled at her words, Celestia seemed to almost panic, the look in Twilight's eyes is one she had seen before.

"Twilight... what are you doing?" Celesta said in an almost whisper, this couldn't happen again could it? How could history repeat itself again? Celestia's thoughts briefly turned to Sunset Shimmer and Nightmare Moon.

"Oh what I always do, have fun!"

"I know your sort of fun... this isn't possible," The Doctor near growled.

"Oh so you recognise me then! Took you long enough!" Twilight half-skipped around The Doctor in twisted glee, "To fool you once... but to fool you twice... in the same way... it was a pleasure."

"Yes, I get that more than I would like to admit..."

"Doctor?" Luna looked at the horrified Time Lord, "Do you know something about Twilight we don't?"

"That's not my name, Twilight was a cover! A disguise so perfect I forgot it was even a disguise!"

"What?" Celestia blurted, her mind was going haywire trying to process what was going on, the others were too shell-shocked to speak.

"I know now that is a surprise isn't it," 'Twilight' feigned shock to mock the group.

"But you can't! You are Princess Twilight Sparkle! Hero of Equestria and friendship made manifest you can't be her!" The Doctor blurted out.

"Yes friendship... you were hardly a model friend when we last met, abandoning me on Skaro at the mercy of crazed tin cans."

"You tried to kill Clara!"

"No... I tried to get you to kill Clara, there's clearly a difference. Not that it matters I have already forgiven you, besides trying to kill each other is basically how we text."

"It was you, you who my vision warned me about..." Celestia tone turned bitter, betrayed.

"Yup! And none of it would have been possible without little Spikey Wikey"

"What did I do?" Spike squeaked out.

"The watch, everything I was, and am once more was stored within. And all I had to do was open it and I returned!"

"So who are you exactly? Missy sounds more of an abbreviation than a name," Luna approached angrily.

"Very clever Lulu..."

Luna seemed ready to tear her head off at being called 'Lulu'.

"She's like me..." The Doctor deadpanned, "A Time Lord".

The princesses stood with their angry expressions while Spike, Derpy and the element bearers stood trembling, no more shock left to give. Fluttershy was the exception, she was crying.

"Time Lady..." 'Twilight' corrected, "And 'Missy' stands for Mistress, but even that's not my real name, the one I chose within Time Lord tradition."

"So what is it then?" Luna snarled.

"Go on Doctor, tell them... I love it when you say my name..."

The Doctor grimaced, but complied.

"The Master"

"Well then Missy, you have pretended to be somepony you aren't and now intend on widespread destruction, and thus have declared a one mare war against Equestria!" Luna declared, the betrayal and hate evident in her voice.

"Oh I know... and I have one thing to say... Doctor..."

The Master approached her old friend until they stood face-to-face.

"HERE... COME... THE DRUMS!"

With a flash of her horn everypony in the room was blinded momentarily, when vision returned the former princess was nowhere to be found.

Silence reigned throughout the hall... within a few minutes their reality's had been smashed, utterly destroyed. It had happened so quickly that nopony knew how to react.

And they saw something that most in that room had never seen, or thought they would see.

Princess Celestia began to cry.