Determined to investigate the death of his old friend Darius, MacLeod follows a lead back to his old stomping grounds in the Pacific Northwest. He meets Joe Dawson, a bookstore owner with a secret; he soon learns that Dawson is a high-ranking member of an ancient secret organization known as The Watchers, who observe and record the lives of the Immortals, passing their archives down from generation to generation. Unbeknownst to Dawson, his brother-in-law, James Horton (the man who killed Darius), has been recruiting Watchers to kill Immortals. We are left with the knowledge that other renegade Watchers may be waiting to try for MacLeod's head.

A mortal named Pallin Wolf, one of the renegade Watchers who believes the Immortals must be eliminated, lures an Immortal to his house and kills him, getting the advantage by tricking him into a sealed room that is completely dark, then stalking him with night vision goggles. Meanwhile, a Gypsy fortuneteller they meet in a restaurant, Greta, warns Tessa that she is in danger. When Tessa is kidnapped by Wolf, MacLeod returns to Greta, asking for her help. But she's mostly a hustler, and not accustomed to getting actual visions, so the clues she is able to provide are meager. Finally, Mac finds Wolf's house, where Wolf is waiting for him. He meets Wolf in the dark room and all seems hopeless until he remembers a matchbook Greta gave him with her phone number in it. Lighting the matches, he regains the advantage and kills Wolf. However, as Tessa and Richie are heading for the car, a young junkie accosts them for money, and in an act of senseless violence, shoots them both. As Mac mourns,

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.

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 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.

In 1944, Ingrid Henning had the chance to kill Adolf Hitler and failed. She's been atoning for that failure ever since by killing dictators, tyrants, racists, and fascists who might have the potential to become as dangerous. MacLeod has a chance to stop her before she kills more mortals, but by stopping her, does MacLeod commit the same evil for which he's judged her guilty?

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

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

MacLeod's old compatriot Hugh Fitzcairn comes to town bearing a mystery -- some of their other Immortal friends have disappeared suspiciously. MacLeod realizes that someone may be following Fitz, and realizes too late that Fitz has put Darius in danger by visiting him. Finding Darius dead in his chapel and Fitzcairn kidnaped, MacLeod won't rest until he finds the men responsible. Tracking the killers of his old friend, MacLeod discovers that there is a band of mortals hunting Immortals, and even holy ground is no protection from them. MacLeod finds the renegades in time to save Fitzcairn and confront James Horton, leader of the Hunters, but Horton eludes his grasp.

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.

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

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.

Warning comes from MacLeod's old friend Darius, a monk over 2000 years old, that Grayson, Darius' one-time protege, is now stalking Darius' other students -- among them, possibly, MacLeod. Grayson, disillusioned that his former comrade-in-arms has become a man of peace, is killing Darius' mortal students in order to draw the monk off holy ground and into combat. MacLeod must protect peace activist Victor Paulus, another of Darius' students, from Grayson's plot to assassinate him. Later he joins Richie and Tessa in France where they will live while Tessa takes up her new job as curator of a traveling collection.

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.

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.

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.

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.

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.

A fellow Immortal, Greg Powers, invites MacLeod to his photography showing. At the gallery, MacLeod becomes deeply disturbed by the violent images of his friend's work, but what becomes more disturbing than the fact that Greg's personality has been replaced by that of a hardened cynic. As he reviews Greg's work, he comes across a photograph taken of himself 50 years ago which triggers a flashback of a time he spent with a young photographer, Linda Plager. In a chance meeting, the now 73 year old Linda recognizes Duncan as her old mentor and lover of 50 years ago, which thoroughly convinces her nurse that she's senile. Upon learning that Linda is dying, MacLeod longs to tell her the truth. Meanwhile, Greg seduces Richie into his destructive lifestyle and coaxes Richie into a dangerous motorcycle stunt. After a confrontation with Macleod, Greg snaps...frustrated by his inability to feel any real emotion because of the insulation from death his immortality gives him, he attacks Richie, an

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.

When MacLeod and Richie are witness to a terrorist attack on an Ambassador, Richie dives in like a Superhero, cocky with Immortality. In the resulting confusion, one of the terrorists is killed, and another, Annie Devlin, an Immortal, is captured. She swears revenge on Richie, and when she escapes from custody, MacLeod takes on the task of educating Richie so that he will have a chance in combat against her. Meanwhile, Flashbacks reveal an earlier friendship between MacLeod and Annie. Mac renews the friendship, and the two Immortals who have both recently lost their lovers find solace in one another. In the end, Richie defeats Annie but can't bring himself to kill her, and MacLeod convinces her to pursue the blood debt no further.

Amanda, the beautiful Immortal cat-burglar returns to town, telling MacLeod she's retired from her life of crime. He doesn't believe her -- especially when two guys start shooting at them. Mac thinks the guys might be Watchers, but in fact they are FBI Agents. Amanda is in possession of some plates for counterfeit money, stolen in Germany before the War. She's looking for an engraver to change the dates, figuring since she's sworn to give up stealing money, she'll have to print some up. Palance, one of the FBI Agents, sets MacLeod and Amanda up to take the fall for his partner's murder, and demands that they turn the plates over. Mac and Amanda are forced to ""die"" on videotape to catch Palance.

Carl Robinson is an Immortal who MacLeod first met in 1929 when he rescued him from a KKK lynch mob. Back then, Carl was full of plans -- to be a Major League Ballplayer, to be President. But today Carl has given up hope. He and MacLeod meet up again when Carl steals Charlie's car. Mac tries to rekindle Carl's belief in himself, but Carl doesn't want to listen. When a white cop named Carter tries to kill him, Carl attributes the incident to racism, until MacLeod explains about the Watchers who are hunting them. After Carter's partner (also white) helps Carl and MacLeod bring Carter down, Carl decides to give the world another chance.

Tommy is an innorcent bystander who's accidentally killed during a swordfight between MacLeod and the Immortal Gallen. Haunted by the unnecessary death, MacLeod tries to find out more about the dead man -- and discovers he isn't exactly the innocent bystander he appeared.