Dean is Mary's first born child, so unlike Sam, Dean had the luxury of having Mary around and caring for him. When Mary and John had tough times, Dean would cheer her up. When Dean was about 2-3 years old, John moved out for a couple of days due to a fight. After talking to him on the phone, Mary would get upset and Dean went and hugged her to tell Mary that John still loved her. Dean last saw her alive when he was four, when John brought him in to Sam's nursery to say goodnight to Sam. Mary was then killed by Azazel. Dean later joins his father on a crusade to find the thing that killed her.
Season 1EditIt's been 22 years since her death, and Dean is still hunting for the thing that killed her. In Pilot, Sam mentions how finding the Yellow-Eyed demon won't bring Mary back. These words anger Dean. Dean still holds his mother's memory dear and will protect it like he protects his family.
Sam later gets a vision about their old house and makes Dean go back to Lawrence, Kansas. Dean had promised himself that he would never go back there, ever since their mother died because of the bad memories (presumably), but agrees to go. When Sam gets trapped by a spirit, Dean rushes into the house to save Sam. When he finds Sam, he see a figure on fire coming towards them and points a gun at it. When Sam stops him, the flames go out and it is revealed the flaming figure was in fact Mary Winchester. Dean is shocked to see her, and Mary smiles at her boy. She moves towards the poltergeist and tells it to leave. She and the poltergeist cancel each other out.
|“||Going to visit Mom's grave? She doesn't even have a grave. There was no body left after the fire. She has a headstone. Yeah, put up by her uncle, a man we've never even met. So you wanna go pay your respects to a slab of granite put up by a stranger? Come on.||”|
— Dean and Sam
in Children Shouldn't Play With Dead Things
Now having lost both his parents, Dean is trying to pull it together. When Sam wants to visit Mary's grave, Dean is against the idea. It's mostly because he doesn't see any value in talking to a place where his mother isn't, plus a reminder on how she really died. How there isn't a body left to be buried. After battling Angela the zombie, they head back to the Impala, and Dean looks back at Mary's grave, before heading off.
In All Hell Breaks Loose - Part 2, Dean finally avenges Mary when he kills Azazel with the last of the original Colt bullets. While Sam is at a loss for words, Dean knows just what to say to the dead demon: "that was for our mom, you son of a bitch."
|“||Sammy, wherever you are... Mom is a babe! I'm going to hell. Again.||”|
in In The Beginning
Thanks to the heavenly intervention of Castiel, Dean is sent back in time and sees a young Mary Campbell. Dean spies on her while she is on a date with John. However, he is noticed by Mary, who comes out and attacks Dean. She almost takes Dean down, but he overpowers her. Then he notices her bracelet and realizes she is a hunter. Dean is shocked with this new information, and would have never thought his mother a hunter. Knowing Dean is also a hunter, she brings him back to meet her parents, Samuel and Deanna Campbell.
Upon confirming that Dean is a hunter, he is invited to dinner. At dinner, Samuel makes comments at Dean but Mary defends him. Later, as Dean is leaving, he talks to Mary. He tells Mary that he likes John, and that they are meant to be (John and Mary). Mary tells Dean that John for her is normal, and everything a hunter isn't. She continues on by saying that she wants out of the hunter lifestyle and she doesn't want to raise her children in this lifestyle. Mary finishes by saying she won't allow her children to become hunters. Dean, knowing she can't do anything about it, feels sorry for her. His mother didn't want this kind of life for him, but her death drove his family into it.
Wanting to save her life, Dean asks Mary for a favor. He asks her to stay in bed on November 2nd, 1983. This way, she won't die and her wish of her children never knowing the hunter lifestyle will come true. Later on, at Liddy's, when Mary is overpowered by Azazel, Dean comes to her rescue, but is shocked to hear Azazel's liking to her. Desperate to save Mary, Dean tries to make a plan to kill Yellow Eyes. When that plan fails, he goes after Mary. Unfortunately, he is too late and arrives just as Mary makes a deal. Dean looks in horror, and knows that he couldn't have stopped her death from coming.
|“||There’s a big difference between dying and never being born! And trust me, we’re okay with it. I promise you that! Well I’m not!||”|
Mary takes them all to a safe house where they prepare for Anna to come at them again. Mary asks Dean to tell her the truth. Dean tries to avoid it but Mary insists. Dean tells her that he is her son, and Mary is shocked by this. She is more horrified that she raised her children in this lifestyle. Dean tells her that she died and it was John who raised them as hunters. He continues by telling her to take Sam and run. Realizing it wouldn't be enough, he then tells Mary to leave John. Mary is shocked by this, and tells Dean she can't, because she is pregnant with him. Dean is shocked at the news. Although Mary will never remember this due to Michael erasing her memory. Dean is not too happy about it due to the fact she will still walk into the nursery and die. Michael tells Dean that Dean knew it was always going happen anyway.
In Dark Side of the Moon, Zachariah uses the memory of Mary to torture Dean. This version of Mary tells Dean that when she died she was glad she could get away from Dean. She also describes how she died to Dean, which pains him. Then Zachariah shows up and touches Mary to anger Dean (which works).
In Mommy Dearest, in order to torture Sam and Dean, Eve turns into Mary. Dean is shocked to see this. Eve tries to use her new form to get them to work for her, but Dean, knowing who his mother really is, refuses. Dean refuses to let Eve get under his skin and kills her while she's in Mary's form, though she turns back into herself as she dies.
Dean is shown to keep a photograph of him and Mary in his room in the Men of Letters bunker. In We Happy Few, The Darkness finds this photograph stashed in a chest, and after Dean helps her reconcile with God, she decides to give Dean back his mother as a gift.
After The Darkness and God depart, Dean enters a wooded area and discovers Mary Winchester, alive and confused, and still wearing the white dress she wore when she died. Shocked, Dean's only response is "Mom?".
Dean is both overjoyed and shocked to see his mother again, while Mary is confused and initially unaware who Dean is, since she remembers him as a 4 years old boy. Dean is forced to reveal to Mary that she has been dead for 33 years, and that he is indeed her son. Dean explains how Mary came back and what has happened so far in short. Mary struggles to take it all in but acknowledges that Dean is her son. The two head back to the bunker where Mary meets Castiel and finds out Sam has been captured. Together, mother and son go to retrieve Sam from Lady Toni Bevell.
Back at the bunker, Mary continues to try and adapt to the changes of the world and that of her sons. Dean is noticeably happy with having her back and gladly eats the pie she buys for him. After a case with a vengeful spirit however, Mary realizes she cannot truly cope with her new life and is unable to truly see Sam and Dean as her little boys, as they are mainly a reminder of all the years she's lost. Mary decides to leave them for a time, which leaves Dean feeling devastated by the news. Mary moves in to hug him but Dean backs away and watches her depart from his life, again.
Dean keeps in contact with Mary through text messages and even plays a game with her at one time. When Sam and Dean participate in Asa Fox's funeral, Dean is bitter to find Mary there, since it means she was willing to drive all the way to Canada for a dead guy and not be there for her sons. After dealing with the demon Jael, mother and sons leave the funeral apparently reconciled.
When Sam and Dean get captured by the Secret Service and don't return home for nearly two months, Mary is angry at Castiel for abandoning her sons. After Dean finally calls them for help, Castiel and Mary contact the British Men of Letters in order to find Sam and Dean's exact location. The four are happily reunited, but Mary soon finds out that Dean had made a deal with Billie in order to escape captivity. Mary decides to take his place and go to The Empty instead, but Castiel stops either of them from doing so by killing Billie.
Relations between mother and son remain fairly stable, though Dean is noticeably affected by who Mary is, because she is not the mother he remembers her to be. Mary is more independent and less motherly than the Mary Winchester he had come to miss, though Sam encourages him to give her time because she is still their mother.
Later on, Mary contacts Sam, Dean and Castiel to help her deal with a case involving a demon. The four of them, including a hunter named Wally, infiltrate the home of Ramiel and try to kill him, only to be intercepted by two demons. One of the demons manages to kill Wally while Sam and Dean kill both demons. Ramiel himself attacks Castiel and leaves him mortally wounded. The three Winchesters are forced to fight Ramiel together. Although they succeed, Ramiel accuses them of having stolen something from him, which Sam and Dean don't understand.
Dean is now very suspicious of his mother, and he and Sam force her to confess. They are shocked and hurt to learn that Mary has been working for the British Men of Letters, since she trusts that they know what they are doing. Dean and Mary soon get into an argument, with Dean ultimately conceding that Mary is her own person, free to make her own decisions, even if he doesn't like them, since they are both adults.
|“|| Dean: How about for once you just try and be a mom. |
Mary: I am your mother. But I am not just a mom, and you are not a child.
Dean: I never was. So, between us and them-
Mary: It's not like that.
Dean: Yeah, Mary, it is. And you made your choice. So there's the door.
— Dean and Mary
in The Raid
Mary's relationship with Dean deteriorates to the point that Dean calls Mary by her first name and insists she leave the bunker. Mary heads for the British Men of Letters compound along with Sam where they take part in Project V. Dean also partakes in the Project (albeit indirectly) when he goes on a mission with Arthur Ketch to hunt vampires. After Sam manages to fend off vampires that intend to raid the compound, Mary and Dean meet up and reconcile, though Dean is visibly discomforted by Mary's decision to let Ketch punish Pierce Moncrieff for the latter's betrayal.
Dean and Mary remain separate for a time. In The Memory Remains, Dean learns from Ketch that Mary is busy hunting a chupacabra.
While Dean deals with a case involving Tasha Banes, Mary comes to the realization that the British Men of Letters are planning to murder her sons. She tries to contact Dean, but Ketch captures her before she can succeed. Dean becomes increasingly worried when he listens to her voice mails as they become more and more frantic, and quickly realizes something is wrong.
Because of her discovery, Mary is captured and tortured extensively by Lady Toni Bevell, who reveals to Mary many secrets kept from her about John. When Sam and Dean successfully capture Toni and bring her to the bunker, a brainwashed Mary joins Ketch in tracking them down. After fighting off a number of Ketch's henchmen that enter the bunker, Sam and Dean are horrified to have Mary aiming a gun at them and siding with Ketch. Mary coldly leaves her sons behind as Ketch locks down the bunker, trapping her sons as they are gradually depleted of oxygen along with an abandoned Toni.
When they escape, the brothers locate Mary at Jody Mills's house. Dean takes Mary back to the bunker and uses Toni to help break Mary free from the brainwashing. Dean speaks to Mary inside her mind and finds her re-living the years she spent when Dean was a child and Sam was a baby. Dean pleads with Mary to realize how difficult life was for him once she was gone, pointing out that he had to be both a mother and a father to Sam and admits to resenting her for making that deal with Azazel.
Dean confesses to both hating and loving his mother, to which Mary finally looks at him in the eyes. Dean is abruptly woken up a moment later by Ketch, who proceeds to attack him viciously. Mary wakes up in time to shoot Ketch and kill him, thus saving her son.
After Sam and his team successfully destroy the compound, Sam returns to the bunker to inform Dean and Mary about Lucifer's escape from confinement. Mary decides to partake in the mission and the three travel to where Lucifer's son is going to be born. They do so with the help of Crowley, who is partially responsible for Lucifer's escape.
While Dean, Sam and Castiel confront Lucifer, Mary stays with Kelly Kline as she begins to deliver Lucifer's son. Following the delivery, Mary exits Kelly's cabin to confront Lucifer. She assaults him relentlessly, leading the two to tumble into a rift that traps them in an alternate universe. Dean is horrified by the loss of his mother, compounded by the death of Castiel at Lucifer's hands.
Dean informs Sam that he believes Mary has been killed by Lucifer. While searching for Kelly's son Jack, Dean prays to God begging him to return Castiel, Mary and Crowley, but he doesn't receive an answer.
While Dean continues to grieve for Castiel and blame the loss on Jack, he is certain that Mary is long gone. He tells Sam that Lucifer ripped Mary's heart out and because of this, Sam should forget about Mary and accept her death. Sam doesn't and points out that unlike Dean, Sam never had a relationship with their mother, noting how it was always the two of them and not him.
When Sam does begin doubting himself, Dean tells him that because he himself is unable to believe in anything, Sam should keep the faith.
When Dean dies and meets with Billie, he confesses his reasons for wanting to stay dead and his inability save Mary is one of them. Billie does not let him die though and sends him back after he tries asking about her.
During The Bad Place, Dean and Sam track down Jack who shows them he has been mastering his powers to see other worlds. Jack then shows both of the Winchesters, the world Mary was trapped in and how she was suffering. Dean was visibly shocked to see that his mother was really alive, even feeling guilty about not considering it. He then told Sam that they would get her back no matter what happened. Indeed, Dean's resolve to find his mother was so extreme he held a Dreamwalker at gunpoint and was willing to let the angels go extinct when they tried to take Jack.
In What Is And What Should Never Be, Dean wishes that Mary never died. Upon an encounter with a Djinn, Dean gets pushed into a world where Mary never died, and as a result, Sam and Dean never became hunters. When Dean discovers she is alive in this world, he rushes over to the house and gives her a big hug. Mary is concerned for her son's strange actions, but lets him stay when he asks. Dean is very happy to spend time with his mother, and even mows the lawn. Unfortunately, Dean realizes that he can't stay here and heads back to reality.