Folsom Prison Blues (S02E19)

After hearing about a ghost that has been killing off inmates one by one, Sam and Dean decide the best way to investigate is from the inside - so they allow themselves to be thrown into a state penitentiary. However, after FBI Agent Henricksen (C. Malik Whitfield) arrives to take over the case, getting out of prison becomes a bigger challenge for the brothers than finding the spirit. (Warner Bros. UK)