Picking up where we left off last season, Sam, Dean and Castiel are left to defend the world after all the souls in hell have been released and are back on Earth and free to kill again.
Sam and Dean hit the road to help an old friend, but it appears that their luck may have finally run out and they are the ones who may be in need of rescue.
Dean and Sam press their luck in a winner-takes-all game of pool. Meanwhile, Castiel hunts down a would-be murderer, but not for reasons one might think.
A search for the one thing that may give the Winchesters an edge against God leads Sam and Dean to Jo's door and to a secret that may have died with a past enemy; Castiel asks Jack to do the unthinkable to help the brothers in their quest.
Sam and Dean are asked to investigate the murder of a childhood friend, calling them back to a hotel from their past and perplexing the brothers with a case they thought was solved a long time ago.
Dean hits the road with Jack who needs to complete a final ritual in the quest to beat Chuck; a difference of opinion leaves Sam and Castiel behind looking for answers to questions of their own.