An American politician is publicly beheaded by three vigilantes and attempt to use a witness as a patsy by killing him with an injection and leaving him at the scene. Instead of killing him, the witness, Barrett Grey, is transformed into a monster resembling a demon. After being ostracized by his city and his wife, the assailants make Barrett an offer. They will help turn Barrett back into his human form in exchange for assassinating the President of the United States, Ethan Offerman.