Professor Allan Neyman and Connor MacLeod create a shield to save Earth from ozone damage in 1999. However, 25 years later, the shield's unintended effects are killing the planet. A terrorist group led by Louise Marcus seeks to destroy the shield. The story flashes back to reveal MacLeod and his friend Juan Sánchez Villa-Lobos Ramírez, two aliens from the planet Zeist, who were banished by the tyrant Katan.

Highlander II: The Quickening
A skilled Highlander, Connor MacLeod, must rush to prevent a global disaster as an anti-ozone shield looms, threatening to devastate the planet.