SUPERNATURAL “On the Head of a Pin” Season 4 Episode 16 March 17, 2009 Supernatural Watch a sneak peek of SUPERNATURAL Season 4 Episode 16 “On the Head of a Pin” airing this Thursday March 19 at 9 pm on the CW. Watch all Supernatural episodes here (Watch Supernatural Episodes) and read all our Supernatural coverage here. Synopsis: SUPERNATURAL “On the Head of a Pin” Season 4 Episode 16 – Someone found Lucifer’s sword and is using it to kill angels. Castiel (Misha Collins) and Uriel (guest star Robert Wisdom) have captured Alastair (guest star Christopher Heyerdahl) and ask Dean (Jensen Ackles) to use the torturing skills he learned in Hell to extract information from him so they can stop the murders. Sam (Jared Padalecki) is concerned Dean can’t handle the job but Dean agrees to do it. However, when Alastair reveals some shocking information, Dean’s world is shattered. Mike Rohl directed the episode written by Ben Edlund (Photos: Courtesy of The CW) Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Google+ (Opens in new window)Click to share on Tumblr (Opens in new window)Click to share on Pocket (Opens in new window)