Dean Winchester | Season One

When Dean was four years old, his mother Mary was killed in his younger brother Sam's bedroom. Twenty-two years later, the Demon responsible for their mother's death kills Sam's girlfriend, Jessica Moore. Together, Dean and Sam go on a road trip to fend off supernatura

l creatures and search for their father, John, who occasionally leaves new missions for them to complete. 

Early in the season "Skin", Dean and Sam battle a shape shifter responsible for a string of brutal murders in the St. Louis, MO area. During the course of the episode, the shape shifter assumes Dean's form, causing police to believe that Dean is responsible for the murders. However, Dean kills the shape shifter while it is still in his form, and the authorities officially declare him dead.

In the last episode of this season "The Demon" possessed Dean's father in an attempt to get The Colt for his own. After Dean realizes this, "The Demon" pins him and Sam to a wall and reveals that John favors Sam over Dean. the demon also tells Dean that he was responsible for sending his children back to hell, after Dean makes a sarcastic remark about the situation, the demon tortures him, Dean pleads for his fathers help before losing consciousness. Sam manages to get free and shoots the demon/John in the leg, releasing the demon from Johns body.

The season finale concluded with Sam, Dean, and John escaping from a clash with "The Demon" in Salvation, Iowa. While Sam was driving to a hospital after Dean and John were injured, a demonically possessed driver drove his truck into the Impala, causing massive damage to the car and the Winchesters inside.