Route 666

S1, E13: Dean is contacted by his first love, Cassie (recurring guest star Megalyn Echikunwoke), an African-American girl who asks him to come to Mississippi to investigate a string of racially motivated murders. Each murder is linked to a mysterious truck that seems to have no driver and leave no tracks. Sam is stunned to see this new side of his brother as Dean struggles to come to grips with the residual feelings he has for Cassie.