Ponies through Equestria envied the way Royal Guards could keep a stoic face, no matter the situation. Little did they know, that the guards themselves envied the Princess for that same exact ability, that surpassed their own. For now the guards were trembling and unsure while Princess Celestia, she kept a stern and emotionless look.

“Proceed,” she ordered with the same tone she used to order a student to clean the chalkboard.

One unicorn guard obeyed and raised a hammer, aiming at the mirror in front of him. He hesitated for a second but, upon looking at the Princess´ commanding reflection, he gulped and smashed the glass with just one hit.

The Princess never changed her expression, not one bit.

*****

Cadence was heading towards the kitchen when she heard sounds coming from the storage room. She peeked and saw a tall, regal figure standing on the dark room, looking small and defeated.

“Aunt Celestia?”

“Oh Cadence, why are you...I mean, can't you sleep, dear niece?” Celestia asked, doing her best to hide her tears.

“Just looking for a warm glass of milk,” Cadence said and noticed a few smalls shards were still on the ground. “Is everything okay, aunt?”

Celestia smiled, a weak, feeble smile and said: “I was just remembering. Remembering old days, old regrets...Cadence, do you think I did the right thing? That I should have...tried something, saying something?”

“Twilight Sparkle said that Sunset Shimmer decision was final. I thought you accepted it.”

“I understand it but I don't want to accept it.”

Cadence placed a hoof on Celestia´s shoulder and then noticed an envelope sticking from her collar. “Have you read her letter?” she asked and Celestia shook her head. “Maybe there you'll find the answers you seek.”

Cadence left the room, leaving Celestia alone with her thoughts. She took a deep breath and levitated the envelope, opening it up to read the content…

****

Dearest teacher:

               First of all, i must apologize for my actions. I can´t apologize enough for all the mistakes I made and for ignoring your advices. I know that you have forgiven me but I still have a hard time forgiving myself.

              I must also thank you for offering me the chance to return to Equestria. Twilight Sparkle explained everything to me but I´m afraid I must reject your offer.

             I will remain here in this world. For, you see, I have found friendship, the very same thing that I always rejected, and it´s as wonderful as you said it´ll be.

            I´ve found love. I met a boy on this world and, while at first my selfishness drove him away, we start speaking again and our friendship and love has rekindled.

           I´ve found a new mentor, so to speak. The rulers of this place, who share both yours and your sister´s name, have take me under their wings, protecting me from the authorities of this worlds and offered me guidance and counsel.

         I´m safe here.

         I´m happy here and I´ve no reason to return to Equestria. I´ve no place there, no longer as your student nor your subject.

        Thank you for everything, Celestia.

                                                                                            Your former student,

                                                                                                                               Sunset Shimmer.

*****

Celestia put down the letter and finally let the shields down. No longer the stern teacher, no longer the regal princess, nor the commanding officer; just a sad mother whose child has left the nest.