"Right. What was that spell you used last time?"
"It was Spherical Prison," Celestia responded. "An advanced and complex version of the common shield spell. It requires pure alicorn magic, no unicorn can conduct this spell. So we should have no trouble with it. Allow me to teach it to you."
Twilight was quick to learn Spherical Prison. To test it and her ability to successfully complete the spell, Celestia had her use a pot of flowers.
She aimed her horn and began, "Shielgorus un sphericana etis impetrano circulus pentalor!"
The floral decor was then surrounded by a transparent purple-tinted sphere, it was perfect. Until it dissipated shortly after Twilight disengaged.
Both alicorns reacted in surprised shock, "What?"
Their curiosity quickly ended and turned into panic as Celestia began to groan in pain.
"This temperature regulation bubble is proving harder to maintain as the sun grows hotter. I am not sure how much longer I can keep it up."
"But, Princess, the spell . . ."
"We have no time to practice more. We must go, now."
"Alright. Don't worry, Princess. Let's . . ."