In their childhood, Sam and Dean Winchester lose their mother Mary to a mysterious supernatural creature, prompting their father John to raise them as hunters to track the creature. The first three seasons focus on the brothers' lives as hunters on the road, beginning with their search for their missing father. Sam is studying at Stanford University with his girlfriend Jessica until she is killed in the same way as his mother. He then leaves school and joins Dean; they travel around the United States hunting monsters, ghosts, demons, and other supernatural beings which are often drawn from folklore and urban legends.
