A capable engineer treats the world as a machine in order to exact revenge for a personal injustice. The enormous human consequences are regrettable collateral damage but an unavoidable part of the logic, at least to the engineer. Set in a medieval world in which one anomalous city state is a guilds-run bureaucratised industrial power.

Published 2005, Part 1 of a trilogy. K.J. Parker is a pseudonym for Tom Holt.