In December 2009, military virologist Lieutenant Colonel Robert Neville loses his wife Zoe and daugher Marley in a helicopter accident during the chacotic qurarantine of Manhattan. A genetically-engineered variant of the measles virus created by Dr. Alice Krippin, meant as a cure for cancer, has mutated in to a lethal strain. It quickly spreads through the world, killing 90% of Humanity. By September 2012, Neville is the last remaining human in New York City - and possibly the world - as he looks for survivors in a wasteland ruled by the rest of the plague's survivors who have degenerated into predatory, cannibalistic beings known as Darkseekers.