I looked at the two blackboards covered in complicated spell calculations and diagrams before I turned to Midnight, raising one eyebrow, "I am better at this stuff than I used to be," I told her, "But I'm still at the two plus two stage. Can you explain this to me in small words?"
Midnight stuck her tongue out at me, "Basically, we almost have it," she said, "I had an idea during the negotiations that seemed to have worked."
"You did math during the negotiations?" I asked and glanced at the blackboard.
She frowned, "What did you think I was doing while nopony was talking?"
"...Okay, dumb question," I admitted. I had spent the time being bored and annoyed.
I mentally ratcheted Midnight and Twilight's estimated intelligence up another couple of notches above myself, "So what do we have?"
"If this pans out," Starlight said from across the table, a pen floating in her magic, "We might have a castable spell ready in a few days to a week."
"That's great news!" I said with a smile, "I thought it would take a lot longer!"
"If this pans out," Midnight cautioned me, "But it's looking good so far, we'll be able to go back soon."
I blinked at that, looking at her, "...You mean I will be able to go back soon."
Midnight shook her head and let out a small sigh, "Page... we're all going home. Me, You, Talon. Because he was right. This was home and it's been amazing seeing everypony again. But this isn't home anymore."
"Starlight, leave the room," I said quietly.
The unicorn almost ran for the door, closing it behind her.
Midnight looked at me as I turned fully to her, "You can't," I told her firmly.
"Can't?" she asked, one eyebrow raising, "I can't?"
"You can't come," I said and sighed, "Ponies here need you."
Midnight stepped forward, her nose almost touching mine, "Ponies? Or Bat Ponies?"
I flinched slightly and took half a step back, "...Both," I said quietly, "What if something happens, they will need the element of magic."
"But that's not what you were thinking of," she said, taking another step forward.
This time I didn't back off, "Don't make it invalid," I told her seriously, "And I might not be able to follow that entire thing," I said and nodded towards the blackboards, "But even I can follow a degrading magical stability ratio. There are only so many times you can do this trip without safely.”
Midnight sighed softly and nodded, taking half a step, moving between me and the blackboard before she sat down, "We might never be able to come back here again safely."
I shook my head, "It's a bad idea," I told her seriously, "Forget the thestrals here, what if they do need your element?"
"Then another will step forward," Midnight said and looked at me, "Page, I'm the element of magic because I was in the right place at the right time with the right ponies. Not because I'm unique."
I sighed, "Fine, what about the bat ponies here, without decursing-"
"A spell any pair of alicorns can do," Midnight told me, "It's not that difficult-"
"Yes it is."
"...Okay, fine. It's relatively not that difficult," she admitted, "It just needs a lot of power behind it to burn through the blood magic. I can teach it to Cadance and Luna. And Celestia."
"Your friends," I said and shook my head, "Your family."
Midnight's ears drooped and nodded, "I will miss them," she said, "I will miss everypony here. But I'd miss everypony at home more."
I shook my head and lowered my voice, "Midnight... Tempest won't last forever," I told her quietly, "And when she's gone..."
"When she's gone," Midnight said firmly, "I will have treasured every second I had with her. And that also applies to everypony here but Cadance, Flurry, Luna and Celestia."
I rubbed my forehead with my hoof. Arguing with any of the Sparkle twins was just an effort in futility. They always had ready answers and often with supporting footnotes. And charts. Not even the lazy ones like pie charts.
But while I found it sexy in Sparks, with Midnight it was just infuriating for some reason.
Shaking my head, I frowned, "What is this coming from, you were... you came down on Talon pretty hard for wanting to go back."
Midnight sighed and then smiled sadly, "I talked to Cadance."
Princess of Love.
I see, yeah that would do it. Fucking damn it, Pink. You just had to, couldn’t help yourself, could you?
"Are you sure?" I asked her quietly, "Because once we go... there might not be a safe way back again."
Midnight nodded, "I know."
"You will have to tell everypony and with me well away from any blast radius. Because I just know I will get blamed for this. Somehow."
"I know," Midnight repeated.
"For the record, I think this is a bad idea," I said before I sighed and looked away, "...But it's not my choice to make. I'll support you whatever choice you do."
Midnight got up and pulled me into a hug.
I hugged back, "...You know, if you two do go back, Talon is likely going to join the guard," I said quietly.
"...Yeah," Midnight admitted and then broke the hug to smile sadly with a small sigh, "Everypony eventually grows up. Even baby dragons."