Sadly, the rest of the break flew by in a blur of spell practice, book hunting, and Totality meeting new ponies as Twilight tried to assimilate back into society and reconnect with her friends. Then, one sunny but cold morning, the two unicorns found themselves saying goodbye on the Ponyville Station platform.
Totality's horn was now a solid dark grey color under a coat of matching horn polish to hide the discoloration until she grew out of it in perhaps a couple of years.
"I can't believe I have to get another assistant so soon," sighed Twilight. "I seriously have no clue what to do."
"The position will be better filled by somepony with less of an ulterior motive," posed Totality.
"Maybe," groaned Twilight, "but things won't be nearly as interesting." She drifted away momentarily in a cloud of worry. "Oh." she suddenly snapped back. "I got you a little going away present." Twilight levitated a silver chain with a multicolored gemstone from her saddlebag.
Totality gasped. "You're spoiling me now."
"I am not. You did a lot for me too, even if it was immaterial and you weren't aware of it." Twilight covered a weird smile with one hoof. "It's one of a kind. I got Rarity to help me with it. Hold it up to the light."
Totality floated the gem up in the sunlight. The gemstone was actually dozens of tiny gemstones cast in polished translucent resin. They sparkled like iridescent confetti.
"Wow, this is so- Wait a minute," she snorted. "Is that your dinky-ass blood crystal in the middle?"
"Eeyup," smiled Twilight. "Now you have two hilarious jokes you can't tell anypony."
"That's so great," laughed Totality, latching the chain around her neck.
Twilight placed a hoof on her shoulder. "Maybe it's just me wanting to vicariously claim your potential accomplishments, but you're like the bratty daughter from out of wedlock I never had."
"Aww," smiled Totality. "There's still time."
"Of course you said that," sighed Twilight flatly. "And maybe someday she'll dress up like you for a school report."
Totality wrapped her forelegs around Twilight but immediately had to begin wiping her own tears away. "You're making this really difficult," she quivered.
"Express to Manehatten," shouted a station attendant. "All aboard!"
The two parted, both trying not to cry as Totality ascended the stairs alone. She opened the window next to her seat for one final goodbye.
"Write me if you need more sources," called Twilight as the engine blasted its initial chug. "I have access to the Canterlot archives again."
"I will," shouted Totality.
"But you have to come here to read them!" added Twilight.
The train pulled out of the station, thundering up to speed and the two continued waving to one another until they were just specks in the distance.