"Not surprisingly, life is hell for Supernatural's Sam (Jared Padalecki) and Dean (Jensen Ackles) Winchester these days. Sam's soul is in Hell, under the control of the demon Crowley (Mark A. Sheppard). To get it back, the demon makes the brothers fetch him the "Alphas," the top dogs of each of the monster species — vampires, fairies and shape-shifters among them — that are running amok. So far, it's a bum deal. "The brothers are tired of Crowley calling the shots," exec producer Sera Gamble says, "so [in the episodes airing December 3 and 10], each of them goes pretty far to try to solve Sam's problem." Powerful angels Castiel (Misha Collins) and Balthazar (Sebastian Roche) get involved, as well as Winchester-hating demon Meg Masters (Rachel Miner)."
Source: TV Guide.com