Immortal Xavier St. Cloud has mortals shoot his Immortal opponents so he can take their heads. Joe tells Duncan about the killings to warn him, and soon St. Cloud and his henchmen show up at the dojo. Duncan discovers the supposedly-dead Horton is working with St. Cloud, and Joe knew that Horton was alive. Meanwhile, an army intelligence officer named Renee Delaney gets involved while she is investigating one of the men working with St. Cloud.
Renee and Duncan are attracted to each other but both are more interested in finding their quarry. Charlie recovers in the hospital from his gunshot wounds. Joe is torn between his loyalty to family and his friendship for Duncan. Nevertheless, he decides to tell Duncan where Horton and St. Cloud are hiding. Duncan confronts them, but they flee to Paris and Duncan and Renee follow them.
A friend of Duncan's is murdered in his pool. After his wake, Duncan notices an immortal named Nicholas Ward, who had once killed several people Duncan knew, arranging his victims to look like a vampire was responsible.
Security advisor Immortal Arthur Drake kills his President just before the signing of a peace treaty. Journalist Beth Vaughan is suspicious of Drake's claim that a sex partner did the murder. Duncan keeps Eli from shooting Drake at the ballet, and Eli tells Duncan how Drake killed his family. Between Eli and Beth, Duncan is drawn into taking Drake down.
Duncan interrupts the attempted theft of an Egyptian sarcophagus. Inside, he finds Nefertiri. As Duncan helps her adjust to modern life, they cross paths with Marcus Constantine, who she resents for his part in the Roman domination of Egypt.
Immortal Luther kills Immortal Rebecca by holding her husband hostage. Amanda, who was once taught by Rebecca, visits Duncan to grieve. They learn that Luther believes in a myth which states that the bearer of a magical crystal will be invincible. Realizing that Luther is trying to reassemble the crystal, which Rebecca had separated and given to her disciples, they try to stop him - but not necessarily together. In flashback to 850 AD, Rebecca rescues newly-Immortal Amanda from being burned with other plague victims and teaches her to be Immortal. In flashback to 1635...
Immortal Paul Karros, who is leading a group of Balkan revolutionaries, comes to the U.S. to try to obtain arms. When a fellow traveler, Father Stephen, is shot, Duncan becomes suspicious of Karros' agenda. Also, Duncan becomes interested in Anne Lindsey, the doctor who treats Father Stephen . Meanwhile, Charlie takes an interest in Mara, a young woman who is helping Karros with his cause.
Michelle, the 18-year-old adopted daughter of one of Duncan's friends, is a not-yet-Immortal until she totals her car and wakes up in the morgue. Duncan tries to comfort her grieving parents and teach her about being Immortal, but Immortal Axel wants to use her and eventually take her head, as he has done to other young woman Immortals.
Immortal Brian Cullen, once Duncan's friend and the best swordsman in Europe, has lost his nerve for fighting and has turned to drugs and alcohol to cope with his problems. After he crashes his car into a bus while chasing after Richie, Duncan attempts to help his old friend get his life together. Also, Duncan asks Anne to dinner after accidentally causing her to fall off her bike while he is jogging.
Duncan and Richie come across an immortal who originally died when he was ten years old, and is therefore stuck in a child's body forever. Realizing that he will be an easy target for full-grown immortals, they decide to protect him.
Duncan is having nightmares and hallucinations of fighting against a shadowy figure wearing a dark, hooded robe. When he meets an old Immortal friend, John Garrick, at Garrick's art show, he discovers Garrick had the same hallucination. Anne wants to know why Duncan has no medical history. Will Duncan gain control of his mind, or is there something more to the problem?
A mortal lawyer named Robert Waverly videotapes Duncan beheading another Immortal, then threatens Duncan with exposure unless Duncan kills Waverly's wife. Meanwhile, the cohort of the Immortal who Duncan killed wants revenge.