On November 2, 1983, Sam and Dean Winchester lost their mother to a demonic supernatural force. In the wake of the tragedy, their father, John, set out to learn everything he could about the paranormal evil ... and how to kill it. In his personal journal, he not only compiled folklore, legend, and superstition about all manner of otherworldly enemies but he also recorded his experiences of hunting the creature that killed his wife even as he raised his two sons.