The Spire is a mountain of metal and stone, a vast city that rises out of the middle of the radioactive desert. Filled with twisting tunnels, grinding elevators, and ancient machinery, it is home to over a million human and non-human residents. Sha, the last of the species known as the Medusi, is responsible for keeping the hodgepodge of forgotten technology and new biology safe as Commander of the City Watch. But when a string of grisly murders are committed just as a new Baroness of the Spire is about to be sworn in, Sha will have to find the killer and bring that individual to justice. With the new Baroness housing a deep hatred of non-humans, Sha will have more than one enemy at her back as a mystery buried in the history of the Spire unravels around her.