Everyone looked ahead to the two princesses.
"What happened next?"
"Well, as you can see, we weren't overturned," Celestia stated flatly.
Luna added on, "the Ancient law has been our own ever since that time, although the degree to which we followed it has wavered over the years."
"Wait, what happened to Firm Sign?"
Celestia and Luna looked at each other. "Nopony knows," Celestia finally admitted.
"Strewth, while there are rumors that he was heard on a nearby mountain ranting that he should have been permitted to refuse his call to warn us, he was never seen again."
They all looked around at each other.
"If she is your mother," Fluttershy finally asked, "what do we do?"
Celestia turned to Luna, who stepped forwards.
"Our mother has not returned from the homelands of old. She shows no signs of having teleported any more than the distance to Ponyville from here, nor does she show signs of having walked, flown, or come here by any conventional means.
"Besides that, the magic in her is different from the way it should be. It is not part of her, but rather it is holding her together, like glue to papier-mâché."
"So she's..." Celestia tried to finish the sentence, but couldn't.
"Indeed," Luna continued, "she is dead, and what we saw is being animated by a malevolent spell, most likely cast by those surrounding her. Her mind has been forced into that body at the cost of the life of whoever that once was, and her body has been transformed to resemble her old self."
Luna paused a moment before continuing.
"Her life is bound to some object, although we know not what. We need to capture the conspirators and make them confess its location. Only then can she be defeated."
"The object wouldn't happen to look like a huge white crystal that glowed green, would it?"
Everypony turned to Feldspar.
"That sounds like an apt description of vitalium crystals, but where wouldst thou have seen them?"
"We saw those ponies in the forest on Nightmare Night. They pulled it out of a huge box."
Obsidian nodded. "We watched them run off when something flying overhead spooked 'em. The ones who brought the box made sure to take it with them."
"And the crystal wasn't just stuck in there either," Kind Face added. "I saw it from on top of a tree. It was in a smaller box stuffed with hay, like the ponies were afraid to break it ."
Luna nodded slowly. "So that is indeed what they used. At least now we know what it is we seek. Thank you three for that.
She turned to her sister, who was sitting down on her haunches and staring into space.
"Is it possible?..." Celestia's voice was barely above a whisper. "If her mind is controlling that body, is it possible that she might change as well? Just as we did?"
Luna stepped over to her sister and nuzzled her. "Perhaps. Perhaps she might, but I fear she may yet be as unyielding as she was when we were but foals."
A single tear fell to the ground, but no one besides the two princesses could tell which one had shed it.
"Take out the two unicorns first, and put a priority on the purple one. She is especially dangerous."
"Yes your majesty."
"Come to think of it..." She turned and gestured to her element bearers. "You find them and take care of them. Surely you would know their weaknesses."
The bearers nodded, then headed out into the dungeons. As soon as they left, the Duke spoke up again.
"What of the two alicorns, your Highness?"
"They will come to me." She smirked. "Just as they always did when they were younger."
Cautiously, they all crept back out of hiding. The three foals, as instructed, made their way deeper into the mines while all the others headed back up towards the castle.
Celestia and Luna made their way to the lower dungeons. From there, they would teleport straight into the port trap to confront Solaria directly.
All the others spread out to search for members who might know where Solaria's crystal was, or perhaps to find the crystal itself.
"Art thou ready, sister?"
Celestia bit her lip and nodded.
The two fired up their teleportation spell and disappeared. They didn't bother to pick a spot. They could feel the trap pulling them back.
In a flash of light, they stood before their mother.
"I wish we could help." Feldspar kicked a loose pebble. "We got pulled all the way here, and now we're told to just hide."
"Well it is for our own safety," Obsidian reminded her. "This isn't like last time. These ponies aren't just out trying to get petty revenge like those other ponies. You heard the princesses. They killed somepony just so they could pretend they have their leader back. They'll probably kill anypony else who gets in the way too."
"I still want to do something."
"How? We don't even have anything to help with."
Kind Face stopped a moment and closed her eyes. She pondered the statement before opening them again.
"We do have something. Come on, further in. We can get out through the original shaft."
With that, she charged forwards.
"Wait a second," Obsidian flapped his wings to keep up. "What do we have?"
Kind Face looked behind her.
"Allies."