Chapter 1: The realization
It had been 3 days since Celestia had last heard from Twilight, her wife and co ruler of equestria. Twilight had been out on a diplomatic mission, with the griffins, Celestia had taken every precaution however, Twilight had a scurrying spell, a tracking, a vital monitor spell, and so many escape spells she was certain if someone so much as touched her it would set them off, and each one would reach to the moon and back so there was no danger of them going out of range, however there was something wrong, the scurrying spell had gone first, then the tracking spell and lastly the vital monitor spell went offline. So either Twilight was dead or something strange had happened. on top of this the only way they could think of that Twilight would disappear would be discord, so he was summoned, however it was proven that he couldn't have done it so that left the final determination. Twilight was dead.
Celestia had been locked in her room for 24 hours at this point, and was completely cutoff from the rest of the world, Luna had tried to get Celestia to talk but all she got was a "no this can't be happening." So it was with a heavy heart she left Celestia to her self. this had been a major mistake on her part because suddenly 24 hours after Celestia separated herself from the rest of the world she gave in.
A massive explosion rocked the castle, from Celestia's room. nearly half the castle was destroyed in this explosion but Celestia didn't care.
Luna however knew exactly what was going on because one tiny detail that everyone overlooked was that right before she became nightmare moon her lover was killed, by one of Celestias guards no less. so Luna knew SOLAR FLARE had been awakened. So she simply said, "well, the griffions will not know what hit them."