An ex-slave turned thief with a a magical metal plate in her head steals a small object from a secure wharfside, accidentally setting most of the place on fire. People start trying to kill her. The guy in charge of the wharf starts to hunt her. In a sort-of steampunk city ruled by four merchant families who control the scrivenings, the ancient alphabet that persuades dumb objects to do things they shouldn't be able to to, she's just found literal key to even more astonishing powers and secrets, and someone is willing to do a lot of killing to get their hands on it and silence her.

A dark setting, but very likeable characters, lots of action, good worldbuilding, a magic system that sort of vaguely feels like computer programming applied to runes make for a very fun read. Bennett just sort of pushes right through the conceptual framework by having everyone, no matter what their educational background, know what 'gravity ' means, then later make a discovery about what gravity *is* which, maybe it wasn't a joke, but i found it funny. Anyway, he sacrifices a certain amount of gritty realism in terms of conceptual understanding for clarity, and it works fine.