A killer who defies definition returns to terrorize the city, forcing a retired detective to confront his past. Homicide detective turned private investigator Frank Morgan is drawn back into the darkness when a murderer, known for blurring the lines between genders and species, reappears after a decade-long absence. Morgan must race against time to understand the killer's motives and methods before more lives are lost, all while grappling with the personal demons this case inevitably stirs.

The premise sets up a dark and suspenseful thriller, likely focusing on the psychological aspects of both the killer and the investigator. The return of a long-dormant, enigmatic killer suggests a narrative that builds tension through mystery and the unraveling of a complex past. Readers can expect a gritty investigation with a focus on the detective's personal struggle to apprehend a perpetrator who defies easy categorization. The genre points to a fast-paced plot with a climactic confrontation.