Point of Sighs: A Novel of Astreiant. Astreiant, #5

Magic, murder and danger in Astreiant. Rumors are swirling among the boatmen that the Riverdeme, the ancient spirit of the river, once bound by the magic of the city's bridges, is back and hunting handsome young men. The broadsheets are full of dire predictions and Adjunct Point Nicolas Rathe has been handed a case that involves a murdered tea trader, a death that implicates a prominent merchant family in the crime.
Philip Eslingen, now a captain in the City Guard, is assigned to assist him in navigating city politics and rivalry between the Points stations, as well as finding the killer. But there are tales from the riverside about extortion and violence and one murder follows another. Philip's stars are bad for water and the Riverdeme is on the prowl.