Waxillium Ladrian, a frontier lawman turned big-city senator, has been on the hunt for the Set, a shadowy organisation led by his late uncle and sister, since they began kidnapping people with the power of Allomancy in their bloodlines. When Detective Marasi Colms and her partner, Wayne, discover stockpiled weapons bound for the Outer City of Bilming, it opens up a new avenue of investigation. Conflict between Elendel and the Outer Cities only benefits the Set, and their tendrils have now reached the Elendel Senate - whose corruption Wax and his wife, Steris, have sought to expose - and Bilming has become even more entangled. Wax discovers a new type of explosive capable of unleashing unprecedented destruction and realises the Set must already possess it,