Dean is working with Castiel to search for Sam in [[12.02 Mamma Mia]], and struggles with the return of his mother Mary. She overhears his conversation with Cas, and Dean tells her he's glad she's back but feels she needs time to adjust. Mary worries that Sam won't be able to forgive her for her deal with [[Azazel]]. Cas calls with a possible location for Sam and texts Dean the address. Mary insists on coming along and Dean argues against it, but loses and Mary joins him. In the car, Mary tells Dean about her time as a hunter, how she was good at it but also realized that all hunters end up dead. Dean tells her about how she died, how it caused John to become obsessed with hunting and raise him and Sam in the life, and how Sam wanted out, but when John went missing, they realized they only had each other. They arrive at the house and join Cas, and while searching the grounds Dean comes across a sigil and disappears. He reappears inside the house where Toni catches him and shoves him into the basement with Sam and threatens to torture him so that Sam will give up information on the American hunters. Mary appears and threatens Toni with a gun, tossing handcuff keys to Dean who releases himself and Sam. Mary and Toni fight but are interrupted by [[Mick Davies]], who apologizes for her behavior and states that the British Men of Letters want to work with them instead.
[[12.03 The Foundry]] begins with [[Mary]] finding a case in Minnesota where people are found dead after reporting hearing a baby crying. [[Sam]] expresses concern over Mary's desire to get back into hunting but [[Dean]] is all for a "family hunting trip". Mary struggles with her lack of knowledge about the technological methods the boys use
, and the aftereffects of the attack. While salting and burning what they think is the ghost's bones, Sam remains concerned about Mary but Dean still believes she's just "adjusting". They return to the room to find Mary gone and upon discovering she's returned to the house, they return to rescue her but she's been possessed by the actual ghost. The ghost tries to make her kill Dean but she resists it and releases him. Dean keeps the ghost occupied while Sam finds the bones and burns them, which releases Mary and the ghosts of all the children in the house. Back in the Bunker, Dean apologies for taking over her case, but becomes hurt and angry when Mary says she has to leave to have some time by herself.
In [[12.04 American Nightmare]] Dean, still upset about [[Mary]]'s departure, travels with [[Sam]] to Mason City, Iowa, to investigate a person who died while being flayed by an invisible force and displaying signs of stigmata. As they discuss the victim, Olivia, with the priest who witnessed her death, Sam notices Dean is very short with him. They wonder if perhaps it was caused by a rogue angel, so Dean calls [[Cas]] to discuss the case. After hanging up with Cas, Dean texts Mary to check in on her and asks if he should still call her Mom. Sam returns and Dean briefs him on Cas' news -- the gates of Heaven are still closed, so it can't be an angel, and he and [[Crowley]] have teamed up to hunt for Lucifer, who has possessed the "Master of Butt-rock" [[Vince Vincente]]. Dean teases Sam when he defends Vince. They head to the morgue to examine Olivia's body, where Dean is dismissive to the medical examiner, and Sam calls him out for being
cranky. Dean is dismissive. Next they question Olivia's former employee and replacement, Beth, who's also a Wiccan . Dean believes she is responsible, but Sam disagrees. A grocery delivery guy is killed in the same fashion, and Olivia's case files show a connection to the Petersons, a "real Old-Testament type" family. They question the family, and afterwards Sam once again questions Dean about Mary's departure and how he's dealing with it, which Dean again brushes off. Discussing the case, Sam believes the ghost of their dead daughter, Magda, is responsible. Dean disagrees, believing Beth is the killer , and leaves to track her down leaving Sam at the farm. Dean questions Beth and determines she was not responsible for Olivia's death when he receives a phone call from Sam , who tells him Magda is still alive before he is attacked and the phone disconnects. Dean rushes back to the farm in time to save Sam, who was about to be poisoned by the Petersons. Afterwards, Dean receives a text from Mary where she apologizes for not getting back to him sooner , and says that she will ''always'' be "Mom".
[[12.05 The One You've Been Waiting For]] finds [[Sam]] and Dean in Columbus, Ohio, to investigate a case of two people falling victim to apparent spontaneous combustion. While investigating the shop where the deaths occurred, Dean finds a hidden room full of Nazi
paraphrenalia. Meanwhile, Sam hacks into the shop's computer and discovers the victims were meeting regarding an antique pocket watch, and that the store owner had a whole business catering to "Nazi nutjobs". He finds out that the pocket watch used to belong to Hitler's inner circle, and the boys presume the [[Thule]] are involved. They call [[Aaron Bass]] to see what the [[Judah Initiative]] knows about any local Thule activity. Aaron tells them they've all come back to Germany regarding a mission called "Das Blut" (The Blood). They ask him about the pocket watch but he doesn't know anything. When news of another spontaneous combustion death pops up, they head to the crime scene -- the apartment of a young woman who managed to escape. They leave the apartment in time to see a cop car driving off, with a woman in the back screaming for help. The follow the cop car to a parking garage where they rescue the woman, [[Ellie]], and tie up her captor for questioning. He is [[Christoph Nauhaus]], the son of [[Commandant Nauhaus]], a ranking officer in the Thule High Command. He explains how the soul of [[Hitler]] is trapped in the pocket watch "like a horcrux", and the Thule plan to use it to resurrect Hitler, along with Ellie's blood, because she happens to be a direct descendant of Hitler -- "Das Blut". The boys convince Ellie to help them set a trap for the Thule, but while fighting Thule thugs, Ellie jumps out of the window and is captured by Nauhaus and Christoph. The boys head to a diner to research a tracking spell to find her, when Christoph arrives, having overheard their location while escaping execution. Christoph leads them to the location where the resurrection ritual is taking place. Handcuffing Christoph in the Impala, they plan their attack. Dean wants to use the [[Grenade Launcher]] but Sam refuses since they need to be stealthy; he promises Dean he'll be able to use it someday. The boys launch their attack but are captured and brought to the room where Hitler's soul has already been transferred into Nauhaus. Ellie is lying on a gurney, weak from blood loss. she staggers from the gurney, grabbing a gun and shooting one of Nauhaus/Hitler's flunkies. Dean uses the distraction to grab a gun and shoots the other flunkies, then shoots Hitler. They walk back to the Impala with Ellie, and Dean exclaims multiple times "I killed Hitler!". They release Christoph and take Ellie back to her apartment. Dean suggests heading for pie , since he deserves it after... killing Hitler!
In [[12.06 Celebrating the Life of Asa Fox]], [[Sam]] and Dean are on their way home from a hunt in Brookings, Idaho, and stop by [[Jody
Mill]]'s house in Sioux Falls to say hi to Claire and Alex. The girls are out of town at a Radiohead concert but Jody invites them in for pizza. Dean of course informs Jody that he killed Hitler. While eating, Dean teases Jody about watching a rom-com movie, and Sam teases Dean about watching anime porn. Jody receives a phone call and gets up to answer it, but afterwards she walks by them without a word and heads for her bedroom, obviously upset. The boys follow and ask her what's wrong, and she tells them a friend of hers died -- [[Asa Fox]] -- and they're having a wake tonight with a hunter's funeral the next day. The boys insist on going with her to support her, and also because they've never been to a hunter's gathering before. She tells them they'll have to get cleaned up before they spend five hours in a car together, as the gathering is in Manitoba, Canada. They arrive and meet Asa's mom [[ Loraine]] and express their condolences. Dean heads to the kitchen to find a beer and introduces himself to the group of hunters there, who are shocked to meet "THE Dean Winchester". A hunter, [[Elvis Katz]] , asks if Sam is there and when Dean confirms he is, he runs out to meet him. Another hunter, [[Bucky Sims]] , asks him if he knew Asa. Dean says he never met him but heard stories about how Asa took out five Wendigos in a night, causing the room of hunters to cheer, as Dean has said the " magic word" and everyone has to drink. Later, Dean wanders into Asa's office where Sam finds him. Dean is impressed, holding an angel blade Asa had, and claims he was legit. Sam talks about how people tell stories about them, and when Dean mentions they're " kinda legendary", Sam says that Asa was too -- then a hunt goes bad and he dies strung up to a tree. Dean says he died on the job, no better way to go. Sam questions this, whereupon Dean explains that they' re not in the "live till you' re 90, die in your sleep" business. Later, most of the hunters have left and only a handful remain. Bucky starts telling stories about Asa and reveals Jody and Asa had a relationship, when [[ Mary]] walks into the room. The boys are surprised to see her but introduce her to Jody, who freaks out and then, seeing the tension between them, leaves to let them talk. Dean asks where she' s been and she tells him she's been all over, using [[John]]'s journal to retrace and catch up on what she's missed. Dean says she could have asked them but she says it was something she had to do on her own. Dean is annoyed, since she only texted them once a week but drove all the way to Canada for Asa, and leaves the room to get some air. Jody intercepts him and mentions that it's odd he didn't tell her about Mary's return, but understands why he's struggling with it and offers an ear if he needs it. Dean thanks her and heads outside. Suddenly [[Billie]] appears, saying she's just finished reaping a soul from inside the house. Dean runs to the door to find it locked. He bangs on the door but Billie says the house is on lockdown and no one can hear him. Dean makes a deal with Billie to get him inside, where he finds out Elvis has been possessed by a demon. They fight, but when Dean starts to exorcise him, the demon snaps Elvis's neck and then leaves his body . The rest of the group joins him, then the lights go out. They light candles and make a devil's trap, but discover the demon has possessed Jody when she accuses Mary of being the demon and tries to get Sam to kill her. The demon taunts them all, revealing various secrets about them. She finally gets to Bucky and makes him admit to killing Asa, before the group, taking turns with the Latin, manages to exorcise it. Bucky explains Asa was hunting the demon, [[ Jael]] , and Bucky tried to get him to turn back to get the angel blade. Asa refused and Bucky pushed him , causing him to hit his head on a rock and killing him. Bucky strung him up on the tree to try and frame Jael for his death. The next morning at Asa's hunters funeral, Billie appears again and says that Dean owes her one for getting him in the house, and wants repayment: Mary. She tells Mary she's offering her mercy since she's so alone. Dean argues that she's not alone, and Mary turns down Billie's "offer". Mary tells the boys she needs just a little more time, and Dean offers to buy her breakfast with all the bacon .
===[[:Category:Season 13|Season 13]]===