Twenty-three years ago, when Sam Winchester was a baby and his brother Dean just a toddler, they lost their mother to a mysterious and demonic supernatural force. In the aftermath of the tragedy, the boys' father John raised his sons to be warriors, teaching them about the creatures that live in the dark corners and on the back roads of America ...and how to kill them. Now Sam and Dean travel the country, ridding small towns and large cities of creatures that most people believe only exist in folklore, superstition, and nightmares.