Twilight freaked out. "The sun is dying and you didn't bother to say anything? How long did you know this was going to happen? Why didn't you say anything about this?! We could have come up with a solution!"

Luna stomped a hoof, "Twilight! Watch your tone!"

"Forgive me, Luna, but don't you agree? Why wouldn't she tell anypony?!"

Celestia, very fatigued, responded almost completely incomprehensibly. "Because telling anypony could eventually lead to societal collapse if it spread too much and to the wrong ponies."

"Why couldn't you fix this anyway, aren't you the princess of the sun and day?"

"It was safer keeping it a royal secret," Celestia continued

Twilight snapped a sarcastic comment at the Princess. "And look how safe we are now."

Fed up with this ridicule and stress from the world ending while keeping Canterlot safe, Celestia shouted back in her royal Canterlot voice. "I tried to fix it myself, but the amulet wouldn't work! The amulet in question can apparently only work once per user in a lifetime! You should understand something fully before going out of your way to shout and criticize like a brute! You're better than that!"

Twilight's soul was shaken to the very core. "Y—you're right, Princess. I don't know what came over me."

The heat of the moment was too much for Celestia, who was already over-fatigued. Her horn suddenly stopped glowing. Frantically, she willed her magic to flow again, but it was no use.

Canterlot imploded from the cave-in of solar heat.