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.

Led by Paul Karros, the people of a tiny Balkan nation are rising up against an oppressive dictator. Karros is an Immortal who once fought his way to freedom with Spartacus. Since then, 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 now. MacLeod turns him down, but Charlie is tempted both by the cause and by Mara.

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.

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" (MacLeod himself) made 200 years before. Flashbacks tell the story of MacLeod coming to the aid of the samurai Hideo Koto after MacLeod is shipwrecked in Japan. 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.