Detective Lacy Powers and her partner John Demmings are stalking a sadistic killer down the rainy streets and back alleys of Providence. Together they go undercover into a dark and perverse subculture, where pimps, hookers and sexual deviants gather at an underground nightclub called Hell's Door. There they come face-to-face with their prime suspect, a charismatic and dangerous woman named Ramsay Wolfe.
But Ramsay might be working in concert with a tortured soul who calls himself Gabriel, an elusive drifter who records each detail of the killings, leaving notebook pages spattered with victims' blood as evidence.
As the headless bodies and blood-soaked crime scenes continue to mount, Lacey and John have few leads and minimal evidence. Will they catch the real killer before it's too late...or will they meet their demise at Hell's Door?