Twilight stopped. She looked up at the balcony. "Spike, go find the mayor and help her if she needs it." She heard Spike's feet running down the hallway. She turned back to the changeling. "I could always use that truth spell."
"You don't really know one, do you? You act like you're better than everyone because you have wings and a horn, but you're just as clueless as the rest of your dumb species. But the great thing about simple minds is that they come with big hearts." It licked its lips. Twilight shuddered with disgust and anger. She shrank the bubble a bit, so that the changeling had just enough room to stand.
"I'm serious. I will keep you here until you tell me what I need to know."
"Is that any way for the princess of friendship to behave?"
"You entered my country without permission, kidnapped a citizen, and impersonated them. That is an act of war."
"And do you really think your friendship skills make you qualified to interrogate an enemy spy?"
"Ah, so you admit you were spying."
The changeling flinched. "And that's all you're getting out of me."
"You were wrong before. I do have a truth spell." I just hope it works. Twilight Sparkle's horn pulsed with magic, and the changeling's voicebox glowed purple.
"Now, how many of you are there?"
The changeling kept its mouth clamped shut, but eventually it blurted out, "I don't know. I only know for sure of the ones in Ponyville. There are twenty five in Ponyville." It snapped its mouth shut and clapped its front hooves over its muzzle, eyes wide.
Twilight sighed with relief that her spell worked, then her eyes widened when she did the math. With the population ratio in Ponyville, ponies still outnumbered changelings two to one, but she knew the ratio had to be higher in big cities. Changelings could easily equal ponies in number, and that wasn't counting the reinforcements in the hive.
"So you do have a brain in that fuzzy head of yours," the changeling sneered.
"Where is your queen," Twilight snarled.
"In the North Mountains beyond Equestria," the changeling blurted out. It cursed under its breath.
Twilight nodded curtly and dissolved the shield and broke the truth and translation spells. She opened the doors and the changeling buzzed its wings and flew away.
Spike ran up to her, waving his arms with panic.
"I can't find Mayor Mare anywhere!"
Twilight gasped. She could be anywhere in Equestria, or beyond! Who knew how many others had disappeared without a trace?
"Right. I'll call the town meeting," she said. She flew outside and spiraled up to the bell. She bucked it, then cringed as it rang in her ear. She flew down to stand in front of town hall. The whole town was there. She could tell by looking. She had known most of these ponies for years. But how long had she really known the real them? I should have asked the changeling how long they'd been there! she realized. She paced back and forth, unable to hide her anxiety. Then she noticed that everypony was staring at her, and forced herself to stand still. Her weight shifted from one hoof to the other and back again as she spoke.
"Citizens of Ponyville, I am speaking to you in place of Mayor Mare because this is a matter of national importance." And also because she disappeared. No need to alarm them any more than they would be.
She cleared her throat when it began to tighten, and continued: "Changelings have invaded Equestria. Nopony knows exactly how many there are or how long they've been here. But I have just recieved intel that there are twenty five here in Ponyville."
Gasps of shock interrupted her and she felt tension spark through the crowd.
"Everypony calm down and listen! We can deal with this! If everypony would get in a single file line so I can use a harmless true form spell, we can drive out the Ponyville changelings." Twilight scanned the crowd, watching especially on the outskirts for possible changelings trying to get away. Everypony thankfully formed an orderly line.
Twilight beamed each pony with the true form spell, which felt like nothing more than a ray of warmth if one was not a changeling. Spike had informed her of this fact when she tested it on him during her studies. About halfway through, she felt lightheaded and her vision blurred. She forced her eyes to focus and keep an eye on the line. So far, nopony had been affected by the spell. Then Cheerilee and a group of her students stepped forward.