Dark Star by C. X. Myers

After the events of the Heights Exclusion, Wally, Vess, and the Dispersers of the Sixth Precinct of Colvus find themselves mired in a city torn by civil strife, all while they grieve their own losses. The civilian deaths in the housing projects targeted by the Cult of the Dark Star have left the Colvian people angry, wounded, and lacking faith in the leadership of the Water Serpent Clergy, who have ruled the city for so many years. In the midst of that strife, Wally must find a way to summon Vess once more without the use of the spirit proxy, Jemma Corsivo discovers a kindred spirit where she least expected it, and a new threat wearing a familiar face rises in the heart of the city.