The first small gestures of rapprochement between the Union and the Free States brings not only hope for the future, but a new terror that no one had quite imagined. Disease attacks those at a governmental function, and those who have succumbed have only a small chance of survival. Can Rook and Thorn, partnered with agents from the Free States of America, get to the bottom of who is spreading disease and why before threats of plague and fire become more than mere hyperbole? Religion and politics swirl together to form a dangerous and explosive mixture from which no one may emerge unscathed.