Episode #5.03, "Free to be you and me," official description:
Not sure he trusts himself anymore, Sam (Jared Padalecki) decides to give up hunting, but a late-night visitor (guest star Adrianne Palicki) won’t let him off the hook that easily. Dean (Jensen Ackles), intent on stopping the Apocalypse, continues hunting on his own and teams up with Castiel (Misha Collins) to find the Archangel Raphael, as Castiel believes Raphael knows God’s location. Miller Tobin directed the episode written by Jeremy Carver (#503).
Source: SpoilerTV.com.