"Call the guard," Celestia started "I fear that if events unfold the way I have always envisioned the would if Sombra were to return..." a pause, a pause Luna knew all to well. It was the pause that Celestia used when saying something that could cause mass panic all across Equestria. The way her sisters head bowed as if regretting something, which as Luna knew she was.
Celestia raised her head and continued this time with a anger in her voice.
"If events unfold the way I have always envisioned them, we can not avoid another crystal war" she finished. Luna walked over to her sister. She knew her sister was revisiting old memories, memories of which nopony should ever have to endure.
"Sister forgive me but you don't have to face this, not alone at least. We have the elements of harmony and they are now embodied by six very smart and capable mares" Luna suggested. She knew well that it was a tough sell, but if her Idea worked there would be no second crystal war. All she had to do was make Celestia believe that the idea was hers, then she would question her and Celestia would become more confident in "her" plan.
"Yes Luna I shall call upon Twilight and tell her to be here by tomorrow morning." Celestia replied "If you can excuse me dear sister I have to go brief the guard captain." with that the solar princess turned around and walked towards the throne room doors, closing them with the royal grace she had almost lost after hearing the situation
An hour later
Celestia sat in her private chambers writing to Twilight to be sure she was expecting her guards arrival. the note read:
My Dear Faithful Student Twilight Sparkle
It has come to my attention that a test is in order for your studies
of friendship. I am sending a guard to retrieve you and if you so wish your
friends may join you but they will have to travel by train. I will include 5 train
tickets for such an occasion but your quick arrival is much needed.
P.S. don't go overboard with your testing supplies you're going to drive poor spike mad.
Sincerely
Princess Celestia
With that she took the note in the golden aura of her magic and surged it to send it to spike.
Celestia heard her door creek open slowly. She looked up to see non other than Luna looking in.
"How many times have I told you to knock?" Celestia asked her younger sister