Nightmare Moon Monologue

Today was the day.

Today Twilight would be successful in convincing Celestia that Nightmare Moon is, indeed, about to return.

There was no way it could possibly go wrong. She dated the earliest mentions, calculated stars' alignment, put it all on a nice and clear chart, and finally had something definite.

A date.

An exact date of when Nightmare Moon was supposed to return from her banishment.

And now she was about to present all the evidence she had to Celestia. It was now or never. Her graphs, quotes from other ponies' works mentioning Nightmare, hell, even the book Twilight received from a mysterious mare a year ago. She had to use all she had.

"Spike!" She yelled over her back. "I'm going to the castle now!"

"Yeah, yeah, got it..."
"This book comes from year 26 A.D.! Nightmare Moon was mentioned even then!"

"Twilight..."

"And here! See this picture? It dates back to 56 A.D. and is said to be drawn by Scarlet Brush herself! And it depicts Nightmare Moon!"

"Twilight."

"A-and these! Those are star maps I've made based on an estimated time of her disappearance! And if my calculations are correct, she will--"

"Twilight Sparkle!" The princess finally snapped and knocked the black, dotted sheet of paper out of her student's magical grip. "That's quite enough."

"But..." - Twilight stood there dumbfounded.

"There are no buts! As there is no Nightmare Moon!" Celestia yelled. Well, not exactly - she never yelled, she was just increasing the power that stood behind her words. And the amount of power she was using now clearly said: obey.

"There was never any Nightmare Moon." The princess continued. "Nor is, nor will be. There never was even any other alicorn besides me. And most certainly there is no pony banished to the Moon. Those are just legends, stories, figments of ponies' imagination.

I would expect you of all ponies to be able to distinguish scientific truth from fairy
The fact she appeared only in legends and children’s stories? Did it really matter? Every legend had a grain of truth after all. And Twilight had sources confirming Nightmare Moon's existence, the old book given to her by a mysterious mare a year ago being the main one. But there was enough evidence scattered around in other pieces of literature! A mare that was fitting Nightmare Moon’s description appeared even in Clover the Clever’s works! It should've been enough to proclaim her research, her theory, plausible and worth further investigation!

Not for Celestia it was not.

Each time Twilight took her new findings to her mentor, each time she had made some sort of breakthrough, the Princess had always dismissed it. “It’s just an old legend” she’d say “A well-known one at that. It fascinated many ponies, just as it fascinates you, and so many versions and mentions of it appeared through the years.”

Twilight did not believe that one bit. It was exactly as the mysterious mare had told her all that time ago: no-one would believe her, but she had to keep going. She had to find out the truth.

And by Faust, she would!

She would search far and wide (as far as books and libraries go, of course), and she would find out the truth about Nightmare