Homicide detective John Hobbes (Denzel Washington) pursues a killer down a bustling sidewalk. There she is: a small, middle-aged woman. No, wait: the killer is the timid man beside her. Now it's someone else. It's all and none of them. Because the murderer Hobbes seeks is a demon passing from one human host to another with a brush of an overcoat or touch of a hand. Hobbes stalks a seemingly immortal foe...An ages-old evil faces a shattering showdown with one, clever tenacious man.