After Midori Koto sees her husband, rich industrialist Michael Kent, murder her lover, she kills Kent and runs to MacLeod for protection. She reminds MacLeod of a vow of protection his ""ancestor"" (actually MacLeod himself) made to her family over 200 years before. Flashbacks tell the story of MacLeod coming to the aid of the samurai Hideo Koto after MacLeod is shipwrecked in Japan. Hideo befriends MacLeod -- even though the penalty for helping a ""barbarian"" in isolationist Japan is death. When Hideo is forced to commit ritual hari kari by his feudal overlord for that crime, MacLeod serves as his second. He vows to Hideo he will always protect the Koto family and is bequeathed the dragon head katana sword he uses to this day. Back in the present, MacLeod discovers that Kent is an Immortal and he's still alive. In order not to further dishonor her family's name, Midori returns to Kent. Kent challenges MacLeod, who fulfills his vow to the Koto family and frees Midori from her loveless mar

Donna, a girl Richie dated briefly several years ago, returns with her 18-month-old son -- who she claims is Richie's! While MacLeod reminds him that it's impossible, that Immortals are unable to have children, Richie sees this as an opportunity to have the family he never had and never will be able to again. When Kern, an evil Immortal, rides into town, MacLeod is reminded of his own foster son, Kahani. Kahani and his Sioux Indian mother, Little Deer, were massacred over a hundred years ago by U.S. soldiers led by Kern, then a mercenary scout. MacLeod is eager to even the score. When Donna finds Richie's sword and demands to know what it's for, Richie is at a loss to tell her. MacLeod advises Richie that it would be safer and kinder to Donna and the baby to leave them. When his new-found family is threatened by Kern, Richie realizes MacLeod is right. While MacLeod rids the world of the evil Kern, Richie lets go of the only family he'll ever have.

The people of a tiny Balkan nation are rising up in arms against an oppressive dictator. The freedom fighters are led by Paul Karros, a vibrant, charismatic leader. Karros is an Immortal who once served as a slave under Roman oppression and fought his way to freedom with Spartacus. Since that time, whenever the common people have been fighting against oppression, Karros has been at their side. Karros and his assistant, Mara, have come to the U.S. to drum up support for their cause. MacLeod and Karros fought together in the Mexican Revolution and Karros tries to convince MacLeod to fight with him in this just cause. MacLeod turns him down, but Charlie is tempted both by the cause and by Mara. When Father Stefan, a local liaison, is critically wounded in an assassination attempt, MacLeod realizes that Karros is determined to fight the war at any cost -- even at the cost of sabotaging peace negotiations by killing those who trust him. When Mara discovers the truth, she threatens to expose

Dawson has a new girlfriend, art historian Lauren Gale, and a new attitude on life. Unfortunately, Dawson arrives at Lauren's house one evening to witness her murder. We discover the murderer is Armand Thorne, benefactor of the Thorne Museum of Antiquities, who was being investigated by Lauren. MacLeod finds an ancient gold cross on display in Thorne's museum, a cross that had been stolen out from under his protection nearly two hundred years before. Armand Thorne, MacLeod discovers, is actually John Durgan, the Immortal trapper who murdered a frontier priest and stole the cross. MacLeod persuades Amanda to come out of cat-burglar retirement and help him to steal the cross from the museum in order to lure Thorne out of his heavily protected fortress. MacLeod confronts Thorne, taking his head, and finally gets fulfill his promise to return the Cross of St. Antoine.

Michelle Webster, the rebellious teenage daughter of a friend of MacLeod's, drives away from her parents' house in a rage and right over a cliff. Trauma surgeon Anne Lindsey tries her best to save Michelle, but it's too late. MacLeod rushes to the hospital to comfort his grieving friends -- and sneak their newly Immortal daughter out of the morgue. He tries to train her in the arts of Immortality, but Michelle just wants to have fun. She meets Immortal Axel Whittaker who promises her all the fun and adventure she could imagine if she stays with him. In flashback, we see that Axel uses beautiful new Immortal women as bait to trap other Immortals and take their heads -- MacLeod barely escaped with his in 1896 Boston. Axel uses Michelle to lure MacLeod to his yacht, where they continue the battle they started a hundred years before. MacLeod defeats Axel. Michelle, witnessing the fearsome power of the Quickening, agrees to be trained as an Immortal under the protection of Amanda.

Cullen, an old friend of MacLeod's, is burnt out from centuries of playing The Game and has turned to drugs and alcohol to get the courage to keep on playing. Cullen had a run-in with Richie and now he's coming for Richie's head. While playing ""chicken"" with Richie on a mountain road, Cullen crashes head-on into a bus full of passengers, killing many. MacLeod tries to convince Cullen, who he once knew as the greatest of the warriors, to stop using the drugs, but a paranoid Cullen believes MacLeod is just trying to render him helpless. Finally, MacLeod has no choice but to confront his former comrade and defeat him.

What happens to a kid who hits Immortality before he hits puberty? MacLeod and Richie take in 10-year-old Kenny, who asks for their protection after the fatherly Immortal who was protecting him is beheaded. Kenny, we discover, is not the sweet little lamb he appears to be. He has been Immortal for nearly 800 years, and has survived all that time by convincing other Immortals to take him in and protect him -- and then taking their heads. Kenny tries to get MacLeod, but he is continuously thwarted by the presence of Anne. Kenny attempts to get Anne out of his way, but MacLeod, realizing the truth about Kenny, manages to rescue her. He goes after Kenny to stop him from killing again, but Kenny manages to escape by blending in with a group of innocent children.

Immortal David Keogh, once an indentured servant, is a noted craftsman with his heart set on marrying his sweetheart, Jill. Unfortunately, Jill does not agree. Although she loved Keogh once, she was unable to handle it when he confided the secret of his Immortality. Now Keogh won't leave her alone and she's coming to MacLeod, whom Keogh respects and might listen to, for help. But Keogh won't listen, convinced that Jill needs him as much as he needs her. In flashback, we see a time in MacLeod's life when he, too, was obsessed with a woman he couldn't have. When Jill is killed in a tragic accident while trying to get way from Keogh, Keogh blames MacLeod and swears vengence.

MacLeod is tormented by visions of his own death, beheaded by a mysterious dark-hooded figure. Anne tries to convince him to seek medical help, but instead he turns to his old friend Garrick, who has spent centuries studying the mind. MacLeod saw Garrick in the 17th Century, when MacLeod barely escaped being burned as a witch. What MacLeod didn't know was that Garrick was not able to escape as well. Garrick convinces MacLeod that the dark-hooded figure is a racial memory that haunts all Immortals and that the way to defeat it is to not fight it, to accept it for what it is. When MacLeod, haggard and exhausted, faces the specter for the last time, puts down his sword and refuses to fight it, the figure goes for MacLeod's head -- until at the last moment MacLeod realizes the figure is Garrick, seeking his revenge after all these years. In the Tag, Anne, frustrated that MacLeod won't open up to her despite their intimate relationship, leaves him.

Lawyer Robert Waverly is leaving his mistress' apartment with his video camera when he sees MacLeod locked in combat with an evil Immortal. Waverly makes sure he gets it all on tape -- the fight, the death, the Quickening. He then tries to cut a deal with MacLeod: if MacLeod kills Waverly's wife, then Waverly won't go to the police. When Kurlow, partner of the Immortal MacLeod killed on the tape, comes after MacLeod, Waverly, unaware of what he's dealing with, proposes another deal. A la ""Strangers on a Train,"" Waverly will kill Kurlow and MacLeod will kill Bruno's wife, and no one will suspect a thing. Waverly challenges Kurlow, who kills Waverly easily and MacLeod is left to save Waverly's wife and get rid of Kurlow.

To save his own hide, petty hoodlum Benny Carbassa, the Nathan Detroit of Immortality, turns MacLeod over to an aging gangster determined to see MacLeod dead before he dies. In the midst of this, Anne returns, having convinced herself that MacLeod will open up in his own time and determined not to push him too hard. In flashback, we see MacLeod's first meeting with Benny, in 1938 at the Coconut Lounge, a club operated by two young brothers who are rivals for the same torch singer.

Recent Immortal Michael Christian has been on an incredible string of luck, taking a number of heads from unarmed and vulnerable opponents, including May-Ling Shen, who taught MacLeod the martial arts in 1780's Mongolia. Christian's Watcher, Rita Luce, has been doing more than just watching, supplying Christian with classified information on the other Immortals and their weaknesses. MacLeod, unaware of Christian, goes on a vision quest to his cabin on Holy Ground -- deliberately leaving his sword behind. The race is on for Joe Dawson to figure out Rita's secret before Christian sets his sights on MacLeod.

When a religious leader, John Kirin, dies on Anne's operating table and then returns from the dead, his believers know a miracle has occurred. MacLeod knows better. He watched as Kirin, then known as Kage, massacred POWs in the Spanish Civil War and left a band of Cambodian refugee children to die at the hands of the Khmer Rouge. Kirin swears that experience changed him forever, turning him from a man of war to a man of peace. When a tabloid reporter trying to get the goods on Kirin winds up dead in MacLeod's dojo, MacLeod is certain Kirin is responsible. Kirin protests his innocence and realizes the real killer is Matthew, one of his faithful disciples trying to protect him. Kirin confronts a disillusioned Matthew, who manages to kill Kirin before dying himself in a rain of police bullets. In the Tag, Kirin and MacLeod have made peace as Kirin takes to the road, hoping to do good elsewhere.

In the 1600s, MacLeod sought refuge for a time in a monastery founded by Paul, another Immortal. There he encountered Kalas, an Immortal monk with a heavenly singing voice. When MacLeod discovered that Kalas was routinely taking the heads of Immortals as they left the sanctuary, MacLeod and Paul expelled Kalas from the monastery, separating him from the music that was his life. Now in the present, Paul and his choir have been lured out of their monastery for a concert tour. When Paul disappears after a concert, MacLeod discovers that Kalas is after his revenge. Meanwhile, two mysterious deaths at the hospital seem to be linked to negligence on Anne's part. Later, when drugs are found in Joe's bar, it becomes obvious that Kalas is trying to destroy MacLeod's friends before coming for him. MacLeod confronts Kalas and finds that Kalas is a strong and skillful fighter, better than MacLeod has faced before, and is nearly the victor. To save himself, MacLeod throws himself off the concert ha

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 two Watchers end up dead by Kalas' hand, Joe realizes that Kalas is looking for Methos, the mythical ""oldest Immortal."" MacLeod knows that, with Methos' quickening, Kalas would finally be strong enough to defeat him. Kalas and MacLeod race to be the first to find Methos. Meanwhile, Richie muscles his way onto a top level motorcycle racing team and the champion, Basil, starts to get nervous. Flashbacks are to Paris in the 1920s, when Kalas, then known as Antonio Neri, was the toast of the opera world. When Kalas threatens a young girl in MacLeod's protection, they fight. Kalas escapes, but not before MacLeod inflicts a throat wound that destroys Kalas' vocal chords and the singing that has been his life since the Middle Ages. Kalas nearly takes Methos in battle and, realizing that he will not be able to defeat Kalas, Methos offers his own head to MacLeod. MacLeod refuses and challenges Kalas on his own, nearly defeating him when the police arrive to send Kalas to prison for the dea

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.

MacLeod decides to tell Anne the truth about his Immortality and she flies to Paris to be with him. En route, Anne helps save the life of a young woman, Tasha, who turns out to be smuggling drugs for the Russian Mafia. Tasha is the lover of Kristov, the head of the Russian gang and formerly the leader of the band of Cossacks MacLeod encountered on his way to the Orient in 1750. Concerned about Tasha, Anne tries to convince her to testify against Kristov, while Kristov is determined to make sure Tasha dies before she can testify. Richie is kidnapped by Kristov as a pawn in this game. MacLeod must choose between taking down Kristov or saving Richie and Richie finds he must grow as an Immortal -- or die.

Father Bernard has a secret he thought he'd buried 50 years ago at the bottom of the Seine. When Ernest Daimler, the Nazi Major who Bernard killed as a young boy and threw in the river, appears at his church looking not a day older than the day he died, Father Bernard realizes he's like MacLeod. As a child, Bernard watched MacLeod die and revive during a mission for the French Resistance and MacLeod swore him to secrecy. Bernard goes to MacLeod for help. Meanwhile, Anne tells MacLeod that she is pregnant -- by an old friend she sought for comfort after MacLeod's ""death."" MacLeod tries to adjust to the concept of being a father. When Daimler kills Father Bernard and comes after Anne, MacLeod kills Daimler and Anne witnesses what being part of MacLeod's life really means. Unable to deal with the part of herself that wanted to see Daimler die, Anne leaves MacLeod.

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.

As Christine tells her tale to the newspaper publisher, MacLeod and Amanda, knowing their world is about to end, finally admit they love each other. Kalas kills Christine and the publisher and steals the computer disk before they have a chance to spread the story. Kalas offers MacLeod a deal -- MacLeod offers up his head or the contents of the disk are made public. Dawson and the Watchers attempt to find Kalas, but this only results in more dead Watchers. Methos tries to talk MacLeod out of it, but MacLeod agrees to fight Kalas on top of the Eiffel Tower. Kalas is defeated and the resulting Quickening, amplified by the Tower, sends a power surge that disrupts every computer in the vicinity -- including Kalas'. The information on the disk is destroyed and Immortals and Watchers maintain their anonymity.