1x13 Route 666

Dean is contacted by his first love, Cassie (Megalyn Echikunwoke), who asks him to come to Cape Girardeau, Missouri to investigate a string of racially motivated murders, one of which was her father. Each murder is linked to a mysterious truck that seems to have no driver and leave no tracks. The brothers eventually discover that Cassie's mother (Kathleen Noone), a white woman, left her boyfriend, Cyrus, for Cassie's African-American father. Cyrus tried to kill him out of anger, but he gained the upper hand and ended up beating Cyrus to death, dumping Cyrus' body and truck in a nearby swamp. The boys assume that Cyrus' spirit has returned and is out for revenge against everyone connected to his death. They attempt to put Cyrus to rest by burning his remains in rusted out truck in the swamp. However, the ghostly truck appears and attempts to run Dean down, and they realize that Cyrus' evil personality had infected the truck, and led it to take on a life of its own. The brothers end up defeating it by having Dean lead it in a chase and tricking it into driving onto the hallowed ground of an old, burned down church. Throughout the episode, Dean struggles to come to grips with his residual feelings for Cassie.