 A dream sequence in "All Hell Breaks Loose" hints at Mary Winchester's connection to Azazel.Although the writers intended to address this in the third season, it was pushed back to the fourth season episode "In the Beginning" due to the 2007–2008 Writers Guild of America strike.Kripke asked Mitch Pileggi to enact this revelation—the two had previously worked together on the series "Tarzan"—and the actor accepted because Kim Manners and much of the "Supernatural" crew had also worked on "The X-Files".