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

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.

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.

ER trauma surgeon Anne Lindsey responds to the call for help after an explosion devastates a subway station, but when a subsequent explosion rocks the station, Anne is trapped. MacLeod remembers WWII London where he and the woman he loved, reporter Diane Terrin, were trapped in a bombed air-raid shelter during the Blitz, running out of time and air. MacLeod is desperate to rescue Anne before he loses her like he lost Diane.