Sophie Montag was an Apicartan woman. She was the younger "sister" of Clara Montag.
Sold into slavery to the wealthy Hiberian merchant Madame Rathbone as a replacement for Clara, Sophie was swept away after Clara killed her master, forcing the two slaves to flee for their lives. They were found by Dagda Vormund, who placed them in the care of Heather Montag, a healer and friend of his. Clara and Sophie both took the surname Montag and began referring to each other as "sister".
While Clara became one of Vormund's most devout followers, Sophie was skeptical. She traveled with the cult surrounding Vormund only to be close to Clara.
Upon their return to the city, they discovered Heather had died in an insane asylum, where she had been forcibly committed by her son. Left with no other options, Sophie stayed with Kirk Babbitt, a retired sailor turned pawnbroker. After speaking with her brother, she decided to leave with him, intending to live with the rest of the Cult of Vormund until better arrangements could be made.
En route to Tyr, she was attacked and killed by Ethan, who had been driven mad by the drug darjeel. Her murder prompted Leonard Gorrister to report the cult to the police, effectively disbanding them and leading to Vormund's heresy trial.