Sam finds a clue to Dean's whereabouts, so he, Mary and Bobby set out to investigate. Castiel imparts some sage advice on Jack, who, still desperate to belong, seeks out a familial connection.
Still trying to solve the mystery of what happened to Dean, Sam enlists the help of Sheriff Jody Mills who may unknowingly already be on the case. Castiel continues to be a father figure to Jack, who surprises even himself, when a life is on the line.
After a hunt gone wrong leaves Maggie's whereabouts unknown, Sam, Dean, Mary and Bobby race to find her, but what they find are their own worst nightmares.
Sam and Charlie team up to get to the bottom of a string of random disappearances; Jack believes that he has found a case and convinces Dean to partner with him on the hunt.
Sam and Castiel track down a Shaman who may be able to help a friend. Nick continues to spiral down a dark path as he looks for answers surrounding the deaths of his wife and son. Jack turns to Dean for help enjoying the human experience.
When Dean and Sam join forces with an unexpected ally, the outcome will alter the course of two lives. Meanwhile, Heaven faces an attack from a dark force, driving Castiel to make an enormous sacrifice to make things right.
Sam and Dean enlist the help of their pal Garth to gain inside information on what Michael may be planning. The brothers split up to each go after weapons that can aid in their fight against the Archangel, but this may be a fight our heroes cannot win.
Michael retakes control of Dean as his army of monsters continue to move in; Sam devises a plan to reach Dean and stop Michael before anyone else dies.
Dean spends some bonding time with Mary and Donna. Nick finally finds the answer he has been searching for. Sam is left to make an unimaginable choice.
To distract themselves from Dean's dire plan, the Winchesters take a case involving dead bodies with mysterious symbols carved in them. Nick's past unveils a shocking desire.
Sam and Dean look to occult lore for a solution to their latest problem, but instead of a resolution, they find much more than either of them had anticipated.
Sam and Dean enlist the help of Rowena to track down a demi-god who feasts on human flesh; the challenge of keeping Michael at bay is proving to be more difficult than originally anticipated.
Sam and Castiel follow a case to a picturesque little town in Arkansas, only to find out nothing is as idyllic as it appears to be. Dean and Jack take a road trip to visit an old friend.
Sam and Dean race to help a friend in need. Meanwhile, Mary is concerned for Jack's wellbeing, and Castiel enlists help from Jo/Anael to track down a miracle.
Sam, Dean and Castiel are thrown into an epic battle. Meanwhile, Jack becomes disenchanted with all the lies, and an old friend from the past shows up.