I Am Legend follows the only human left on earth: Robert Neville. The aftereffects of a nuclear war mutated the human gene and made them what Robert calls “vampires”, dead creatures that inhabit the human body, attack at night and are allergic to garlic. During the beginning of the book, Robert constantly tries finding a cure or a way to reverse the effects of the plague. He also fights to stay alive as vampires try breaking and attacking his house every night. In his free time, Robert listens to loud music and drinks himself filthy.
While Neville tries finding a cure and learn more about vampires in general, he experiments and looks at the inactive bodies of vampires and sees how they react to different components, such as garlic and sunlight. He also reads books about classic vampires such as Dracula. During one of the days Robert is researching, he meets a live dog who becomes his new best friend. The dog is later killed by the vampires, leaving Robert even more lonely than he initially was.
We learn about Robert’s wife, Virginia, during the time she caught the plague. When she died, Robert was filled with too much grief to burn his wife, which was the only way to ensure she doesn’t rise from the dead as a vampire. Instead, he buried her. When she did come back, he had to kill her once more. Robert also remembers that a preacher has said that the plague was punishment for all human sins, and Robert finds out that the cross does, in fact, repel vampires.
After a while, Robert gets used to the life of a vampire hunter, and he even enjoys it as it becomes a routine. One day, the routine is broken as he sees a woman walking in daylight. He manages to catch her even though she tries running away from him. Ruth, the woman he catches, acts as human as he does. His hopes of restarting the human race again is heightened, but he wishes to make sure she is human. He does this by checking both garlic and sunlight on her, but when he says he wants to check her blood, she hits him unconscious and runs away.
He finds a letter when he wakes up where she has explained that there are vampires that are fighting the plague. They are trying to eliminate both the remaining humans and vampires. Robert doesn’t hide, which she urges him to do, and ends up killing himself by using a pill given by Ruth, before the vampires are able to kill him.
