In a world devastated by a plague that has annihilated almost all of humanity, Robert Neville, a military researcher, becomes the last living man in Los Angeles. His existence is a daily struggle for survival in a city now dominated by nocturnal creatures, a mutant species of humans who have succumbed to the disease and are immune to daylight. With each dawn, Neville seeks ways to keep himself safe in his fortified home while investigating a potential antidote for the disease that ravaged civilization.
With loneliness as his only companion, Neville clings to memories of his former life, finding solace in the toys and keepsakes that surround him. However, the reality of his isolation becomes increasingly oppressive. His routine is interrupted when he encounters other survivors, a small group struggling to survive and also facing the nocturnal beings. This meeting confronts him with hope and the moral dilemma of what it means to be human in a world that has drastically changed.
As the plot unfolds, the story becomes an exploration of fear, loneliness, and the last vestiges of civilization, leading Neville to a heart-wrenching decision that could change the fate of humanity. A palpable tension arises as each encounter brings him closer to an uncertain future.