In the opening sequence Solomon Kane (James Purefoy of THE FOLLOWING) is fighting in the Crusades in the Middle East. All of his men are slaughtered. He confronts a demon,who tells him that he's bound for hell because of his violent ways. So he renounces being a soldier and returns to England, keeping to himself until a Puritan family befriends him. We learn that he was part of a noble family that he left as a young man--he and his older brother got in fight and the brother went over a cliff, presumably to his death. Now, this land is now ruled by an evil sorcerer. In fact, it turns out that the brother survived and is now this zombie-like creature that can infect others with evil just by touching them. After the family encounters some of these demonized soldiers they are killed--except for the daughter. So he takes it upon himself, against incredible ods to go and rescue her.
Of Robert E. Howard's book characters I always preferred Conan and Kull over Solmon--but this is the best film adaptation of any Robert E. Howard character.