Supernatural: Season 4 Episode 18: The Monster at the End of This Book
Starring: Jared Padalecki, Jensen Ackles, Jim Beaver, Genevieve Padalecki, Misha Collins, Traci Dinwiddie, Scott Parsons
Length: 43 minutes
Supernatural: S04E18 Description: An author has been writing books about Sam and Dean since 2005. Sam and Dean try to figure out how he knows so much about them.