S5, E20: The Devil You Know
Sam and Dean face off against the Horsemen! The demon Crowley (guest star Mark Sheppard) tells Sam and Dean he can help them find the remaining Horsemen rings so they can trap Lucifer. The brothers are doubtful until Crowley leads them to Brady (guest star Eric Johnson), the Handler for Pestilence (guest star Matt Frewer) and Death. However, Brady refuses to give up their locations and sets Pestilence after the Winchesters.
Starring Mark Sheppard, Eric Johnson, Matt Frewer