He fought his first battle on the Scottish Highlands in 1536. He will fight his greatest battle on the streets of New York City in 1986. His name is Connor MacLeod. He is immortal.

In the year 2024, the ozone layer is believed to have been destroyed, and it's up to MacLeod and Ramirez to set things right. Opposition comes from both the planet Zeist (MacLeod and Ramirez's homeworld) and a corporation profiting from the supposed lack of ozone. Also, flashbacks show the story behind MacLeod and Ramirez's exile from Zeist.

Immortals Connor and Duncan Macleod join forces against a man from Connor's distant past in the highlands of Scotland, Kell, an immensely powerful immortal who leads an army of equally powerful and deadly immortal swordsmen and assassins. No immortal alive has been able to defeat Kell yet, and neither Connor nor Duncan are skilled enough themselves to take him on and live. The two of them eventually come to one inevitable conclusion; one of them must die so that the combined power of both the Highlanders can bring down Kell for good. There can be only one... the question is, who will it be?

Starts off in the 15th century, with Connor McLeod training with another immortal swordsman, the Japanese sorcerer Nakano. When an evil immortal named Kane kills the old wizard, the resulting battle leaves him buried in an underground cave. When Kane resurfaces in the 20th century to create havoc, it's up to McLeod to stop him.

The world is falling into chaos. As he roams a crumbling city, Duncan MacLeod, the Highlander, remembers happier times before the love of his life left... Hopeless and alone, MacLeod finds his way to a band of immortal companions, including his mysterious friend Methos, and a mortal, Watcher Joe Dawson. Together this small group sets out on a quest to find the origin of the first Immortal.