Fire Brandy's three secretly named children, harvested boiler after boiler and never returned to her.
Carl and Katia Grim both tried to get Fire Brandy off The Nightmare Express for the sake of her babies. Brandy corrected them: it was three babies this time, not two. Talking with Tizquick had recovered her memories of previous lives in a boiler — an engine controlling the heat for a massive boat, and before that a castle's heating system. Each time she had thought it was simply a job to earn money for her children, and each time she was given one, sometimes two, this time three.
Against the custom of not naming them before the ceremony, she had named every one of them, and each name was different. None had ever returned to her, though she always came back. Refusing to be used that way again, she chose to burn with the train. Carl understood afterward that she had killed herself to save herself from losing more children.
Boiler-born demon offspring, three this time, each secretly given its own name.
The stolen children whose loss drives Fire Brandy's suicide and reveals the dungeon's harvesting of its NPCs.