Supernatural Season 6 Episode 3 (Supernatural s06e03) with title “The Third Man” aired on Friday, October 8th 2010 at 09:00 pm via CW Network.
Here is summary for Supernatural Season 6 Episode 3 :

Sam and Dean call Castiel for help when they investigate a case about several dead police officers who seem to have been killed by the plagues of Egypt. Castiel confirms the staff of Moses was used to kill the cops and tells Sam and Dean that Heaven is in a state of chaos and God’s weapons have been stolen. The three head off to find the thief and come face to face with an old enemy.