One mouth later.

The ancient archives storage in Canterlot, everything seemed to be quite we except the mice that call this place there home. There was thousands of artifacts and ancient history that Celestia and Luna keep safe here form the eye of the ponies, secrets that will never be told to anyone. The artifacts that are in here like the Celestia's and Luna's war armor it has not been use sense the day King Sombra first took the Crystal Empire. Next to it them are two mirrors, one is orange and one is blue. They when where doors to a another world. Celestia has been in the orange one, it was a world of opposite of this world. The blue was not explore, as Celestia did not want to interfere with this the mirror worlds. But something is wrong with the blue one, it waved like water. Suddenly a pony came out her mane and tail looked like fire, her fur was light orange. She was a unicorn. She was wearing a leather black jacket and a orange with her cutie mark. She had a dark orange skirt with a pick and yellow strip, she had black hoove shoes.

She got up and rubbed her head as she looked her. "This is not where I once was in when I was in that human world, Celesita might just moved it here in, the archives. Great." She said hoping to find a was out.

She spotted the armor. "I hope that was not used by them. Well they may have too if Celestia had to in a thousand years ago to defeat King Sombra."

She soon walked want try to find the exit, the place was like a maze. There was thousand of books and scrolls that date back before the founding of the nation of Equestria. Some where two thousand years old that socket the mare. "Wow thats old, thousand years old book of 'The History of The Shadow Crystal Empire'. Odd that doesn't seem right." She said.

Next to it was 'The Northern Crusade, End of the Empire'. "That's Gusty The Great of the cover? Why does she have a unicorn skull but the horn is cured and like a crystal? In her hand?" She said it a questionable looked. Gusty had a sadistic grin and was looking at the skull. The skull had sharp teeth. "What has Celestia been hiding to every pony?!"

She found the exit. She open the door and she was in Canterlot Castle, it was morning. As she walked in the hallways until she heard some ponies walking. "Guard duty is the most boring job but it is good pay." the guard said. The guards saw the mare. "Hey how did you get here."

She raised her hands. "Hello there, I'm looking Celestia."

The guards looked at each other and then looked at her. "Miss why did we need to bring you to Celestia."

She smiled. "Tell her 'Sunset Shimmer has return'."

....

Princess Celestia and Princess Luna sat on there thrones. The princess of the Sun with her white and gold dress had a list as she looked at what she had to do today "Lets see, Lets see." she said. Celestia has been busy as she has plans when the crystal empire, reappears. Like increasing the army and wonderbolts. The navy was not important to her as the empire had took rainbowfall and the only train rail to Griffonia there is no way King Sombra will have a navy. And luckily every pony that lived in rainbowfall evacuated.

The princess of the Moon with her dark blue dress, looked at her sister and smiled. "You really want to do this Sister." Celestia looked at her. "I promise I would, sister."

"Even if Equestria had not been at war for over one thousand years, sister." Luna said.

"Yes I know." She said but pausing. Luna was right, Equestria had never been at war, but she and her sister don't know what Sombra was planing. "But I guess once the empire returns we may need spies in it to understand Sombra and what he is planing." Luna smiled. "I Agree with that."

Suddenly a royal guard opened the door "Excused me your majesties, but there is some pony here that wants Princess Celestia." Celestia had a questionable looked on her face "Who is this pony."

"Her name is Sunset Shimmer." The Princess of Sun gasp and dropped the scroll in her hands. Princess Luna looked at her "Sister are ok." Celestia looked at Luna. "Yes I'm... I'm fine. Guard bring her to me."

"Yes Princess" Guard said and walked out can the door close. Luna was still had a odd looked on her face. "Who is Sunset Shimmer." Celestia took a deep breathe and realist it "My other student. The one I try to teach her friendship and alway questions me about the mirror door. I guess in her exile in that world she must have come back to forgive." The door open, the guard was right there "Here she is." There she is, Sunset Shimmer. She walked slowly to her former teacher. "Princess Celestia, I come as a change pony. I am sorry that I did that to you, for disobeying you teachings. I come here to your forgiveness."

Princess Celestia smile and got up. She then walked to Sunset and hugged her. "I miss you Sunset Shimmer." Celestia said with tears coming from her eyes. Luna need that Celestia had many students. They then stop hugging, Sunset looked at her teach "So what has change since I was gone." Celestia's face change form happy to sad. "Its a long story."

Princess Celestia tried her best to explain everything. It was hard for her to not cry when she said Twilight Sparkle. But Sunset was sad that she never met her. Sunset was done talking about the world. "So that world?" Celestia said. "Is just a mirror of this world right."

Sunset smiled "Ya it is, In that world there know had humans and they don't have tails or fur or long ears."

"I see." Celesita saying "I have something for you to do."

Sunset smiled "And what is it."

Celestia cleared her throat "I want you to go to ponyville and find Twilight's friends. They are the Elements of harmony and with out the element of magic. I don't think that Equestria can't defeat King Sombra."

"He had return." Sunset said and was shocked.

"Yes, I believe that you are the last hope of the element of magic." Princess Celestia said. "I will do my best Pirncess." Sunset said.

Sunset walked out and head to ponyvile. Luna looked at her sister in a questionable looked. "You really think she can use the element of magic." Celestia sighed "She is the only pony that has magic that is strong as Twilight."

Author's Note

Sunset Shimmer returns to her teacher I wonder that will make any pony mad.