A refitted virus designed to cure cancer has gone horribly awry, doling out gruesome death to 90 percent of the world's population and transforming almost all of the rest of humanity into sun-intolerant, bloodthirsty mutants. By day virologist Robert Neville prowls the grass-grown hulk of a dead Manhattan, alone apart from his German Shepherd Sam, hunting the wild deer that now bound through the deserted streets when he's not in the lab under his Washington Square townhouse still desperately seeking a cure to reverse the plague that has already ravaged the world. He himself is immune, but has met only frustration in trying to pass his immunity on to the infected. His daily challenge is to meet any other survivors at the South Street Seaport, near the destroyed hulk of the Brooklyn Bridge, echoes emptily through the radio bands. By night his home becomes a fortress. The moment the sun escapes the sky the creatures stream forth from the dark hives in which they wait out the day, seeking blood. They have become aware of this lone survivor walking the streets of New York, killing them when he finds them. An alpha male among the once-human creatures, inflamed with animal passion, has become obsessed with finding Neville and destroying him. As Neville clings desperately to the shreds of his sanity and to Sam after three years alone in an increasingly wild and post-human New York, he is tracked down by the creatures and targeted with his own traps, leaving him to wonder whether there's any future for himself and for humanity.