Following the spread of a fatal disease which resulted from a potential "cure" to cancer gone awry, Robert Neville (Will Smith) finds himself the only survivor left as the infected, both humans and animals alike, swarm the streets each night. Accompanied by his dog, perhaps his greatest ally in the remaining world, Robert struggles to stay alive among such rabid creatures. Among the overgrowth consuming New York City, he fights just to find food with each sunrise, and returns to his dark shelter with nightfall. However, his routine is about to see a drastic turn of events.