I Am Legend is a 1954 horror fiction novel by American writer Richard Matheson. It was influential in the development of the zombie genre and in popularizing the concept of a worldwide apocalypse due to disease. The novel was a success and was adapted to film as The Last Man on Earth in 1964, as The Omega Man in 1971, and as I Am Legend in 2007, along with a direct-to-video 2007 production capitalizing on that film, I Am Omega. The novel was also the inspiration behind the 1968 film Night of the Living Dead.
Neville survives by barricading himself by sunset inside his house, further protected by garlic, mirrors, and crucifixes. Swarms of vampires, led by Neville’s neighbor, Ben Cortman, regularly surround his house, trying to find ways to get inside. During the day, he scavenges for supplies and searches out the inactive vampires, driving stakes into their hearts to kill them. He finds brief solace in a stray dog that finds its way to his house. Desperate for company, Neville slowly earns the dog’s trust with food and brings it into the house. Despite his efforts, the dog proves to be infected and dies a week later.
After bouts of depression and alcoholism, Neville decides to find out the scientific cause of the pandemic. He obtains books and other research materials from a library, and through painstaking research discovers the root of the disease in a strain of bacteria capable of infecting both deceased and living hosts. He also discovers that the vampires are affected by the garlic, mirrors, and crosses because of “hysterical blindness”, the result of previous psychological conditioning of the infected. Driven insane by the disease, the infected now react as they believe they should when confronted with these items. Even then, their reaction is constrained to the beliefs of the particular person; for example, a Christian vampire would fear the cross, but a Jewish vampire would not.