Katia's ex-husband, who left her for one of his students — a wound Eva reaches for as a weapon.
Fannar belongs to Katia Grim's life before the dungeon, and he surfaces only because Eva Sigrid chooses to use him. Mocking Katia in her own voice aboard the Vermillion train, Eva throws two of her private griefs at her: that Fannar left her for one of his students, and that she was not going to be allowed to adopt. The detail lands as evidence of how close the two women once were — these are the confidences of long lunches in Reykjavik, now repurposed as knives.
Nothing else about him is known: he never appears, and Katia does not answer the taunt. What the moment establishes is the shape of the life Katia came from, a marriage that ended in humiliation and a wanted child she was refused, and why being told she was useful might have mattered enough to get her killed.
Never seen or described; known only as the husband who left Katia for one of his students.
Katia's absent ex-husband, invoked as a taunt to break her.