The oldest and most dangerous organization in the world is rearing its head in the city of Chicago. It's been in existence since the dawn of man, and now secretly serving as members are some of the most prominent people in the city who have sold their souls for worldly goods.

Unnatural occurrences of killings and deaths are a result, and what is dubbed the M.O.T.B. (Mark of the Beast) murders prompt homicide detective Lt. Christian to seek help from his priest and psychiatrist friend Dr. Kailin, who has extensive knowledge in the matter and has written a book on the obscure organization invoking these activities.

The two pair up to investigate and track the organization's roots in hell, discovering a deeper plot to seize and imprison "Good Souls" in an attempt to convert them into damned ones. In the struggle to deliver the city of Chicago out of this perilous bondage, others destined to unite with Lt. Christian and Dr. Kailin help infiltrate the organization, and a new war against evil is waged.