Centers on the events leading up to the cataclysmic 1980 eruption of Mount St. Helens in Washington, with the story beginning on the day volcanic activity started on March 20, 1980, and ending on the day of the eruption, May 18, 1980.

Troubled police detective Jack Lucas is falsely accused of a series of murders and must prove his innocence by catching the real serial killer.

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 Ziest (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 Ziest.

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.