As Charlie regains strength, MacLeod accepts help from Dawson one last time, and barely misses catching Xavier and Horton. He then follows their trail to Paris -- accompanied by the persistent Renee Delaney. They track down Horton, and when he almost escapes, he is shot by Joe Dawson. MacLeod, with the help of his humorous new neighbor Maurice, then tracks down Xavier and finally takes his head. In a coda, however, we learn that Horton still lives.

In 1918 in the Soviet Union, MacLeod promised the Immortal Drakov that he would not fight him, in return for seeing lives spared. Today Drakov, now called Arthur Drake, still operates behind the scenes of international politics, a cruel puppetmaster who is dragging Eastern Europe toward anarchy. Eli Jarmel, an old man whose family was destroyed by Drake, urges MacLeod to recant his promise, while Beth Vaughn, a reporter, puts her life in danger by investigating both Drake and MacLeod.

MacLeod feels the Buzz coming from an ancient sarcophagus and opens it to find Nefertiri, Cleopatra's handmaid, buried 2000 years ago with her mistress. Now revived, she pursues a vendetta against the Immortal Marcus Constantine, who was her lover and her enemy. Mac believes Constantine, who claims that he no longer wishes to fight Nefertiri -- this former Roman General has turned his back on battle and is now a curator, working to preserve history and its lessons. But Nefertiri can't let go of the old grudge, and for the first time, MacLeod is forced to face a woman he loves in Immortal combat.

When her mentor Rebecca is killed, Amanda is determined to avenge the death, even though it means going up against the formidable Immortal Luther, and very possibly losing her head. She comes to Mac for a final fling before her likely death, and when he discovers that she's after Luther, he tries to take the battle on himself, feeling he has a better chance of survival. Together they discover that Luther is hunting the pieces of an ancient crystal that Rebecca divided among her students, believing that the whole crystal will make him invulnerable and ensure that he is the Last Immortal. In the final confrontation, both Amanda and MacLeod take their turns battling the ascetic Luther.

Richie returns, on the run, turning to MacLeod for help. An Immortal has been following him, refusing to confront him, but committing grisly murders wherever Richie goes. Richie is arrested for the murders. Mac learns that Immortal hunter Martin Hyde is behind the murders: considering the Quickening of a green Immortal like Richie not worth the taking, Hyde has been hounding him in order to drive him to his teacher. MacLeod must clear Richie of the murders and defeat the evil Immortal.

MacLeod is picked up at the airport in France by his old friend, Hugh Fitzcairn. For the first time in the 350 years MacLeod has known him. Fitz has settled down as a Universitv Professor with the love of his life, Naomi. Flashbacks show MacLeod and Fitz's first meeting, when MacLeod was protecting the Doge's daughter from Fitz's amourous advances in Venice, 1637. When Naomi's jealous ex-lover is found strangled next to a computer displaying Fitz's falsified teaching credentials, Fitz goes on the run from the police. MacLeod realizes that Fitz is being framed by Kalas, who has followed him from the U.S. Kalas challenges Fitz and takes his head while MacLeod watches, unable to interfere.

When Immortal Ceirdwyn and her mortal husband are gunned down by a street gang, she calls upon her skills as an ancient Celtic warrior to exact her revenge on the members of the gang, one by one. At the racetrack watching Richie's success at racing, MacLeod befriends a young pickpocket, the brother of one of the gang members, and learns of the killings. MacLeod, who has known Ceirdwyn since before they helped smuggle Bonnie Prince Charlie out of Scotland in 1746, feels he must stop Ceirdwyn and make her see that revenge is not the answer -- a lesson she helped MacLeod learn in the bloody aftermath of Culloden. In return, Ceirdwyn helps MacLeod see that, although loving a mortal can be dangerous for the mortal, it is the mortal who must choose whether to take the risk. MacLeod calls Anne. Meanwhile, Richie ""dies"" in a firey crash during a race, a crash that also takes the life of the champion, Basil.

When a valuable DaVinci sketch is stolen from a friend of MacLeod's in a robbery that killed two guards, MacLeod offers to act as go-between to ransom it back. He discovers the sketch was stolen by Kagan, an Immortal he faced once before, when Kagan was a bank robber in 1930 Paris and MacLeod killed his mentor. Meanwhile, Maurice asks MacLeod to talk to his troubled niece, Simone. Simone turns out to be more troubled than Maurice knows -- she's a prostitute and Kagan's accomplice. MacLeod goes after Kagan, who protests his innocence in the deaths of the guards and who promises MacLeod that he'll change his ways if MacLeod will help him. When Simone, the only one who knows Kagan is the killer, is killed, MacLeod realizes that Kagan could never really change and confronts Kagan, taking his head.

Amanda accidentally helps Kalas escape from prison by trying to do MacLeod a favor and kill Kalas for him. After an attempt on Maurice's life thwarted by MacLeod, Kalas kidnaps Amanda to use as bait against MacLeod, but Amanda manages to escape. Meanwhile, Christine Salzer, the widow of a Watcher killed by Kalas (in ""Methos"") decides to get her revenge on Immortals and Watchers alike by exposing their secret to the media. Dawson and Methos team up to try and talk Christine out of it, but she's determined to take a computer disk with the identities of all known Immortals and Watchers on it to a newspaper publisher. Dawson, desperate, tries to kill her outside the newspaper building, but is stopped by MacLeod and Methos. Christine enters the building and the Immortals and the Watcher know their lives are about to change forever.

Lord Byron, the brilliant Romantic poet, is alive and well and living the decadent life of a rock star. He lives life way over the edge and has taken some promising young musicians over the edge with him. When following in Byron's footsteps tragically ends the life of Dawson's protege, MacLeod is faced with a decision -- is the beauty and genius that is Byron worth the cost?