Richie Ryan tries to protect an old girlfriend, Nikki, from a band of drug dealers. This puts them both in jeopardy from an Immortal, Voshin, whom MacLeod knows from an adventure during the Second World War when he was trying to smuggle Jewish refugees out of occupied Eastern Europe. Nikki complicates the story by withholding drug money she has stolen from the gang, thinking she can use it to make a better life for her small daughter. Tessa, meanwhile, becomes enamored of the child, raising issues for her and MacLeod.

Tessa witnesses the murder of a painter, Anne Wheeler, but the absence of a body leads everyone but MacLeod to doubt her story. MacLeod supports Tessa in her quest to obtain justice for Anne. It develops that Anne was killed by her Immortal ex-lover, to keep her from revealing his secret. After Tessa is taken to a police safe house, MacLeod realizes that the killer is in fact the Chief of Detectives, and he must rescue Tessa and bring justice to Anne's killer.

Thirty years ago, evil Immortal Quenten Barnes was executed in the electric chair, and promised he'd be back. Escaping the tomb that he has been captive to for the last several decades, Barnes begins hunting down the people involved in his execution. Joe Dawson learns that he has returned and tries to get MacLeod involved in Barnes' apprehension. Mac declines to get involved unless Barnes gets in his way, but when his old friend Michael Moore comes to town, a flashback shows us that Barnes killed Michael's wife and has a long-standing grudge against Michael. Now Mac is involved. He convinces Dawson to share the Watchers' surveillance file on Barnes with him. However, the file isn't much help. As the prosecutor and priest who were at Barnes' execution are killed off one by one, it becomes clear that Barnes will come after Michael next. The story ends with an interesting twist as MacLeod must make a decision that will affect the ""lives"" of two different personalities.

Xavier St. Cloud returns, killing Immortals with the help of mortal mercenaries who shoot his prey, making his kill easy. His next target is MacLeod but, warned by Dawson, Mac and Charlie just manage to escape death -- though the dojo is all but destroyed in the gunfight. Renee Delaney, a CID agent investigating the mercenary angle, gets on the case. MacLeod goes after Xavier himself, and Charlie insists on coming along. During his battle with St. Cloud, MacLeod spots James Horton, the Hunter who killed Darius. Distracted, Mac is 'killed' and falls down an elevator shaft out of beheading range, and Charlie is badly wounded and lies near death. Blaming Dawson for helping Horton escape alive, MacLeod warns him not to cross his path again.

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.

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.

Joe Dawson arrives in Paris to let MacLeod know that Horton may still be alive and coming after him. However, when MacLeod meets Lisa Milon, a dead-ringer for Tessa (Lisa Halle after plastic surgery), all thoughts of Horton and the Watchers go out of his head. Richie, unsure if Mac is thinking clearly, goes to Dawson for help and winds up taking a bullet for him when Horton tries a hit. Lisa is kidnapped, and MacLeod insists on going after her even though his friends warn him it may be a setup. He can't take a chance on burying her again. When Lisa finally tries to kill MacLeod, he turns the tables on her and Horton at long last gets what's coming to him.

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.

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.

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 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.

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.

McLoud bought a Celtic bracelet once given to the love of his mortal life and after her tragic death he buried it with her. He returns to Glen Finnin to return the bracelet to her grave and learns of several gruesome ritualistic killings based around the one immortal who killed Mac's father. Naturally Mac must get to the bottom of the killings and keep his head in the process.

MacLeod's old friend, Kit O'Brady, comes into town in search of a good race horse and a change of luck. MacLeod knew Kit back in Gold Rush San Francisco, when Kit ran the Double Eagle Saloon. Kit lost the Double Eagle to Amanda in a poker game and has blamed her ever since for his string of bad luck -- and he's vowed to kill her. When Amanda chooses to breeze back into MacLeod's life while Kit is there, MacLeod is hard pressed to keep them apart and to keep them from killing each other.

An ancient statue of the Hindu goddess Kali is purchased by the university where MacLeod teaches and is put on display. Its creator, Immortal Kamir, who has been searching for it for centuries, arrives determined to take it back to its' home in India. Deva Ennis, the half-Indian department chairman who found the piece for the university, is equally determined to keep it. MacLeod, who has known Kamir since the Raj period, when India was controlled by the British Empire, knows Kamir is the last of the Thugee, a cult who worshipped Kali by ritually strangling her enemies.

The Immortal Coltec is a Native American Hayoka -- a shaman whose responsibility is to take evil into himself to protect his people. After the massacre of MacLeod's Indian family in 1872, Coltec saved MacLeod by taking in the evil and rage he felt. Since the death of his tribe, Coltec has become Hayoka to the world, protecting it from evil Immortals. But Coltec's capacity for evil isn't endless and when evil finally overtakes hin, MacLeod must find a way to save Coltec without being drawn into the evil himself.

MacLeod arrives in France, leaving a trail of hate and destruction in his wake. Methos finds him and discovers just how evil MacLeod has become when he tries to take Methos' head on holy ground. After MacLeod kills another good friend, Methos realizes that the only way to save MacLeod may be to kill him.

When MacLeod was but a wee lad in the village of Glenfinnan, he thought Cassandra, the Witch of Donan Woods, was only a myth, a fairy tale concocted by crafty old men to frighten unwary children-- until the night she found him alone in Donan Woods. Now, four hundred years later, Cassandra comes to MacLeod again, this time to tell him of his role in an ancient prophecy -- that only Duncan MacLeod can challenge and defeat the voice of darkness.

Carl Robinson, the former slave turned baseball player, has finally found the good life as a Major Leagues star -- but when Carl is challenged by another Immortal and witnesses find him standing over the decapitated body, Carl is forced to go on the run from the cops. He turns to MacLeod for help when he is pursued by lawman Matthew McCormick, who has more than just a professional interest in taking Carl into custody.

Richie's found a new teacher: an Immortal who preaches a message of peace. An Immortal who believes that all Immortals can lay down their swords and live together as brothers. An Immortal who claims to be the oldest of their kind still alive -- Methos. Will laying down his sword in the name of peace mean Richie will lose his head? And what does this mean for the friend MacLeod already calls Methos?

MacLeod knew him as Melvin Koren, a desperado who left a trail of death and fire across the Old West, but Cassandra remembers him as an evil far older. He is Kronos, leader of the Four Horsemen, mounted Bronze Age raiders who murdered, raped, and pillaged their way across two continents. Never was a band of Immortals more cruel or more feared. He destroyed Cassandra's people and she's been hunting him across the millenia. But Kronos has a different target now -- Methos.

The Chateau LeMartin has been in Marina's family for generations, but now the slimy Carlo Capodimonte threatens to foreclose on an old loan and take the chateau for himself. Desperate to save the family heritage, Marina kidnaps an American millionaire in order to pay off the loan. Unfortunately for Marina, the rich and charming ""Richard Redstone"" she has tied up in the cellar is none other than Richie Ryan.

Are MacLeod and the police seeing a ghost when the evidence in a diamond theft and poison gas murder points to the very evil, but very dead, Xavier St. Cloud? CID Agent Renee Delaney returns to ask for MacLeod's help in finding the killer. Could it be Xavier or simply a memorial to a fallen teacher by Xavier's former student, Morgan D'Estaing?

The dead are walking the streets of Paris. The forces of evil are coming. Is MacLeod being readied for some higher calling -- or is he simply losing his mind?

Once every thousand years, the Zoroastrian demon Ahriman returns to wreak havoc on the earth. He has already brought destruction to Duncan MacLeod's world, having caused Richie's death at Duncan's hand. But now MacLeod returns to Paris to take up his mantle as Champion and vows to destroy Ahriman. Sophie Baines knows how to defeat the demon, but is she MacLeod's ally, or another pawn in Ahriman's game?

Police at her heels, killers on her trail, Kyra is on the run, with no memory of who -- or what -- she is. In the streets of Paris, she runs into Duncan MacLeod, who spins a wild story: that he and Kyra were lovers once, some three hundred years ago. That she is a soldier, a warrior. That she is Immortal. Kyra doesn't believe a word of it... but if it isn't true, then why is someone after her head?

The popular series lays down its sword after six seasons in this stirring finale, in which MacLeod makes the ultimate sacrifice to save the lives of Amanda and Joe Dawson... then reunites with old friend Hugh Fitzcairn, and gets a look at what the world-- and his friends' lives-- would be like without him.

Fitz died three hundred years ago... Horton has taken over the Watchers... Joe Dawson has been reduced to a bitter, penniless vagrant... Amanda is a black widow... and Methos has rejoined the Horsemen to avenge his fiance's death. If you think that's bad, just wait till you find out what's happened to Richie and Tessa.