Here is the official description for the Friday, December 2 episode of Supernatural.
BOBBY REVISITS HIS PAST — As Sam (Jared Padalecki) and Dean (Jensen Ackles) race the clock on a high-stakes mission, Bobby (Jim Beaver) seeks the help of an unlikely old friend to solve one of the most personal cases of his life. Robert Singer directed the episode written by Sera Gamble (#710).
