In the premiere episode, parapsychologist Dr. Sara Beckman is attempting to use a demon-summoning device, which serves its purpose all too well. The mysterious Raphael Cain shows up and rescues her, only to be accidentally shot by Sara for his pains. Goodwin whisks Raphael off, but needs Sara's car and apartment to buy him time to heal. The demons, led by Mallos and his ""assistant"" Vashista, see Beckman's device as a threat and try to track her down. Raphael manages to drive them off, but when he has to stop to rescue Sara, Goodwin is captured by the demonic duo.

In part 2, Mallos and Vashista torment Goodwin and use him as bait to draw in Raphael. The plan succeeds, but only after Mallos has sadistically ripped off Vashista's hand and sent her back to Hell himself. In their final battle, Mallos taunts Raphael with the fact that his daughter Kiyomi is still alive and out there...somewhere. He then manages to escape. Raphael and Sara recover Goodwin, and they decide to make Sara part of their team, bringing her scientific expertise on-board.

McQueen, an aging rock star, has a deprogramming center for demons on his farm. Raphael is skeptical about reforming evil, though Sara tries to see things from a scientific angle. Added to the mix is Randall, a deadly demon bounty hunter from hell whose agenda is to behead demons who have seen the light of goodness. In the end, it turns out to be a demon ruse designed to crush McQueen's hopes.

A demon body-jumper is the Immortal's newest threat: immune to his sword, it jumps bodies with impunity, including the body of Sara's romantic interest: a detective investigating the series of bizarre murders it leaves behind. Ultimately the trio track it to a hospital where it plans to take over the body of a senator and spread chaos from such a high position. Raphael discovers that the demon is vulnerable to electricity, and weakens it long enough to use his sword to send it back to Hell.

Deciding to take a break, the trio check into a ""fantasy suite"" type hotel, unaware that it is a haven for demon. Through the fantasy-decorated hotel rooms, guests are sent to a extra-dimensional region with the same motif, and used as a plaything for demons on ""vacation"". Sara and Goodwin take on the roles of a saloon girl and Billy the Kid, and Raphael must rescue them. He manages to break the enchantment over them, by wooing Sara and letting Goodwin-as-Billy shoot him down in a gunfight. He then goes after and defeats the head demon of the ""resort,"" freeing the rest of the prisoners from the spell and returning them to reality.