Thousands of miles away, high above the surface of Equestria, orbited a moon. I should know; astronomy is one of my many special talents.
On that moon, stood a very, very bored horse looking through a telescope it had somehow constructed out of moon rock.
"Oh, minions," she shouted evily, "it appears that Celestia's prized pupil is no longer around to defend her. Canterlot shall be mine for taking. BWAHAHAHAH!" Lightning would have flashed at this moment, but there was no lightning on the moon. There also were no minions.
But as she peered through the telescope to track Twilight Sparkle, though at this point in time the moon horse did not yet know the small studious unicorn's name, so she simply referred to her as "Awkward Small Purple One", she noticed that the mare had come into contact with a most fetching batpony. Wow, what a looker. Nightmare Moon, as the horse called herself, blushed. "Something something moon innuendo pun," she whinnied. "Sure, I'll bring about everlasting night when I return, but I have a secondary mission now: Make senpai notice me!"