Fluttershy, of course, hadn't flown off with the other pegasi. "I need you with me," I told her.
"Oh, okay," she said, quietly.
"Princess Celestia, Princess Luna, I need your guards, and I really need you to take shelter... against what I just demonstrated. Rarity? Could you entertain them?"
"I surely could."
"Everypony else, I need you go that way," I pointed behind me as I began flying in the direction of the bipeds.
Notably, the Princesses didn't balk, though I wished they had. Had they, they would have known better what to do, and they had the experience to know better. That they let me proceed...
It frightened me, almost more than that they had already teleported away, leaving their guard behind.
The ponies of Ponyville were in danger. I swallowed hard as I directed the armored ponies to spread out at about 45º and to call out, not attack, when they spotted the intruders, and to stay back. My hoof-cannon demonstration had made that point easy.
Starlight galloped below us. "What about me?"
"And me?" Fluttershy asked, somehow flying fast and making doing so appear languid.
"We need to catch the bipeds—" I started.
Starlight galloped and jumped, suddenly glowing green as she took flight in her magic beside me. "And flying would be faster. Naturally."
I coughed. As the hue and cry split up going down various streets, I said to Fluttershy, "The bipeds are riding horses, giant ones, that for them are simple animals. I want you to speak to them."
"Riding them? The horses will have a lot to say about that!"
"And your plan?" Starlight asked. "You always have a plan."
Again, I swallowed hard. Thinking of AJ and her honesty, I said, "Make sure no creature gets hurt or gets away to tell the others there are other ponies besides ponies that look like their non-magical horses."
"You're trusting your instincts again, and admitting it?" Starlight said and smiled. She made a knocking gesture toward my head. "Are you a changeling?"
"No."
"Good. I like this new confident Twilight."
Fluttershy said, "Uh huh!"
I felt my face warm. With the sudden fall of night, and that the lamplighters had not made the rounds, the moon was dim enough to protect me from total embarrassment. Block after block of shadow shrouded houses and storefronts breezed by. Everypony left here had taken my earlier advice to remain indoors. The horses had long legs and probably ran like the wind.
Fluttershy added, "You know, we're headed away from Sweet Apple Acres."
"Right! That's actually better. They can't just run back to their fellows."
"And towards the Everfree Forest."
"Then, for their safety, we must stop them."
I heard shouts, then a pegasus guard swooped between brick chimneys and flew along side us. "Your Highness, follow me."
We banked up and over thatched roofs far to the left, passing over Sugar Cube Corner. The guards, most of them furred white or light blue, their brass armor gleaming in the light of the moon, were hard to miss, but they had managed to corral the intruders on three sides where the houses ended and a park area led up to the forest. The giant horses were undoubtedly as fast as the wind, but one of the two, the irascible one of the pair, was demonstratively unhappy, and kept looking up and around, and balking. He clearly sensed the pegasi. Few ponies would deny feeling a shock seeing the shadow of wings cross the path they trotted along. Large eagles and rocs did that to anypony. It was an instinctual horse-brain fear of predators.
"What'll we do?" Starlight asked.
"Keep your distance, everypony. I'm going to cast a shield."
"I can do that, too."
"We aren't deflecting force spells or arrows, Starlight. It's a bead of lead flying faster than the speed of sound. You heard the sonic boom."
"I did. Mine has a time component—"
"Why doesn't that surprise me?"
"It allows me to dodge. What else?"
I rattled off an effective mass-vector range necessary for a EDD-standard spellbook Shield spell. Starlight whistled as I added, "Fluttershy will convince the animals to stop and we’ll convince the bipeds to dismount; the guards need to fly around trying to convince them not to run while staying far enough away that they cannot be accurately shot at."
The stallion biped helped. He kneed his horse and yelled, but now the animal's own muddled thoughts consumed him. The giant horse didn't want to go straight, shying left or right depending on what he saw, and the companion mare stayed alongside despite them being within a hundred pony lengths from the forest line.
I landed and cast Shield. It was barely large enough for me and Fluttershy to stay behind. The tuning necessary to stop supersonic beads of lead heavily restricted the size of the spherical arc segment I could magically manifest.
Starlight disappeared. The guard made like distant flitting ghosts.
The horse stallion danced about as I approached and the red aura of the shield reflected in his eyes. The biped mare reached repeatedly to catch his bridle, but couldn't. He shied away when a green aura surrounded the stallion biped, but Starlight couldn't unhorse him because of the tack he had his feet in, and his grip on the animal's barrel. The bipeds shouted until the biped mare slapped the stallion's flank.
His horse jumped into motion and a few heartbeats later, she dashed afterward.
I saw Starlight flying amongst the trees of the forest, then land on a high branch.
Her levitation spells hadn't served to unhorse the bipeds. Instead, she suddenly bent down a branch as the horses rode in.
The wet-sounding crack was shocking.