A/N: I was rereading CP2 and this kind of came out. Enjoy! :)
"I shall see you on Blackfriars Bridge, Tessa."
His voice echoed in her mind, devoid of the gentleness she had come to associate with him. Despite his tone, the way he said her name would always remain the same; it left her spine tingling with pleasure even now. Her heart clenched as she silently reminded herself that she would only be seeing him once a year at the place where they fell in love. They both knew not how he would change, but it was certain that this would be the last time she ever saw him as James Carstairs. Brother Zachariah is only a shell of the Jem she knew.
He was gone now, leaving a cold, dry scent in her room. It made her miss that smell of smoke and burnt sugar he had before he became a Silent Brother. Tessa knew she would miss many things about Jem: the way he displayed his soul when he played the violin, how his kindness never failed to fix even the grumpiest of moods- including Church, who was always a grumpy cat unless he was with Jem- and of course, the positive outlook he had on his short life. He suffered, but never sought vengeance, never been bitter to anyone. Tessa admired this attitude, but could never reflect it. Jem was unique and no one could replace him.
So why hadn't she been able to say goodbye? Because it was not true, she realized. Jem would be back; they would find a cure no matter how long it took. Saying goodbye would have been like giving up hope, and she was not willing to do that—was never willing to do it. She would search the world if that meant she could free him from the eternal darkness of Brotherhood. He would be able to coax beautiful melodies from his violin again, breathe the fresh air, and see the light of day…
The search could take years, decades, even centuries. But in the end, it would be worth it. This was not goodbye forever. Tessa clung onto the final thread of hope as she gazed out the window to see the Silent Brother's carriage headed toward the Institute gates. She released a whisper after it that Jem would never hear:
"Mizpah."