In the year 2024, the Earth is suffering from the depletion of the ozone layer, leading to harmful UV radiation penetrating the atmosphere. Connor MacLeod, an immortal who has won The Prize, is now an aging man living in a dystopian world. He spearheaded the creation of an artificial shield to protect humanity from the sun, but this shield has left the Earth in a perpetual state of darkness. A rebellion arises, questioning whether the shield is still necessary, as rumors spread that the ozone layer has healed. Meanwhile, Connor, facing the deterioration of his own health, is suddenly rejuvenated when his old friend, Juan Sánchez-Villalobos Ramírez, returns.

Connor learns about the true origin of the immortals and his own past, revealing a deeper connection to an alien planet named Zeist. General Katana, a tyrant from Zeist, is sent to Earth to kill Connor, fearing his potential return to Zeist. This sets off a series of conflicts, combining sword fights and advanced technology, as Connor must confront both his extraterrestrial origins and the political corruption surrounding the shield corporation on Earth. Pursuing the truth about his past and the future of humanity, Connor joins forces with Louise Marcus, a determined environmental activist, to challenge the shield and confront the forces threatening both his life and the planet's fate.