Supernatural Guest cast, played by Mark Rolston Episode 4x09: I Know What You Did Last Summer (Nov 13, 2008) Episode 4x10: Heaven and Hell (Nov 20, 2008) Guest cast, played by Christopher Heyerdahl Episode 4x15: Death Takes a Holiday (Mar 12, 2009) Episode 4x16: On the Head of a Pin (Mar 19, 2009) Episode 4x21: When the Levee Breaks (May 7, 2009)