"We're here." The elder alicorn examines the musky air that fills the cavern, alongside her faithful student.
 
"Celestia..." Twilight views the princess, concerned of her age. "You need rest..."
 
Twilight motions Celestia down unto the ground, but she refuses. "Twilight Sparkle... For thousands of years, you have watched over your ever growing city of Ponyville. You have knowledge far beyond any other creature that has ever existed throughout Equestria. Not even I know of such math and science." She looks over to Twilight, who wears a faint smile, and caresses her hair. "You have been through so much. From spreading friendship throughout this world, to banishing the purest of evil." Celestia looks down with a worried expression. "... It is time I reveal to you this land's darkest secret."
 
"A... secret?" She looks as if she's about to say something else, but does not.
 
"Yes." She uncovers the dust upon the ground with her hoof, revealing several small spheres.
 
"... Princess?"
 
Celestia lifts up a sphere out of the seemingly dozens of them. She then casts a small light upon the object, revealing a skull. Only the nose is pushed into a smaller form.
 
"What is..." Twilight steps back.
 
Celestia sighs. "Many, many eons ago, there were beings before us. Very, incredibly intelligent organisms. There were the ones that helped one another through rough times, and then..." She gulps. "Then there were the remaining, which had declared war upon one another."
 
Twilight observes the seemingly hundreds of various bones that scattered the ground. "I don't understand... Why? Why were they so cruel to one another? Why... are they gone, princess?"
 
Celestia takes a deep breath, and her horn begins to glow. A light at the very back of the cave appears, but then grows to the point where she could tell the room was far larger than she could comprehend. Large structures cast their shadows upon the two mares. Several rotting, fallen buildings are spread throughout the perimeter.
 
"What... What is this place?"
 
The light abruptly recedes, and Celestia falls to the ground.
 
"Celestia!" Twilight leans down to support her back up.
 
"I'm... I-I'm alright." She makes out, getting back on her hooves, shivering.
 
"We must get you back to Canterlot for first aid, now!" Lifting Celestia onto her back, she begins the walk back to the cave entrance.
 
As Twilight steps into the blizzard outside, Celestia takes one last glance into the cave before sealing it off for thousands of years to come.
 
Celestia mumbles to herself as a tear streams down her cheek. "They destroyed themselves with their own being. Their own creations. I can only pray the same doesn't happen to us."