I Am Legend
, by Richard Matheson, is a classic of the horror genre, and is a disturbing take on vampires, society, and personal struggles. A plague has set upon the entire world and the governments enacted draconian laws and procedures to try to contain the outbreak. But these efforts failed, society collapsed, and people died. Those who remained struggled to survive against a fast-moving, unknown infection, and those who died started returning at night, looking for blood.
The book focuses on Robert Neville as he tries to stay alive and sane in a world ruled by vampires. He researches the plague and tries to find a cure, and his strength and reason are put to the test in a life where his days are spent preparing for the vampire onslaughts at night, and his nights are spent struggling to live to just another day. Trying to stay alive while all alone, especially after one’s family and friends are killed and the only purpose in living any longer is to avoid being ripped to shreds by vampires, can test anyone’s sanity, and Robert has his share of mental, as well as physical, struggles.
I haven’t yet seen Hollywood’s remake of the book, the I Am Legend 
movie, and I understand Hollywood changed the original story quite a bit (even turning the English-German, blond-haired Robert Neville into Will Smith), but the read was so haunting that I am hesitant to see the movie production. The book, at least, is recommended.