Season 10 aired on Tuesdays following The Flash. It was later moved to Wednesdays, following Arrow.
Season 10 begins with Sam's frantic search for his missing brother, who is gone without a trace. The road to recovering the wayward Dean takes Sam down dark paths, with consequences that will shake the boys to their core. Along the way, Sam encounters a former US marine named Cole Trenton, who apparently knows Dean and wants revenge for Dean killing his father. Meanwhile, Castiel, with the aid of Hannah, has to pick up the pieces in the aftermath of Metatron's campaign. But with his grace failing and rogue angels still on the loose, Cas faces the ticking clock of his own mortality. After Sam learns that Dean is a demon, because of Crowley and the Mark of Cain, Sam eventually finds him, with help from Crowley, but so does Cole. While Dean and Cole meet and duke it out, Dean overpowers Cole and nearly kills him. But Sam manages to trap Dean with holy water and handcuffs carved with devils-trap symbols.
After giving Crowley the First Blade, Sam takes Dean back to the Men of Letters bunker to cure him. Castiel and Hannah are on the way to help but are delayed because of a rogue angel who injures Cas and tortures Hannah until Crowley shows and takes the grace of the angel and gives it to Cas. As Sam continues to cure Dean, he eventually escapes the devil's trap and tries to kill Sam but Castiel arrives, overpowers Dean and they continue curing him until he is finally human. As the season progresses, all-new threats emerge to once again push all of our heroes to their limits.
One such threat is the appearance of a very powerful witch named Rowena, who also turns out to be Crowley's mother and has the power to kill demons. He captures her, but she convinces him to let her live in Hell so they can reunite and be a family again. Meanwhile, while Castiel and Hannah still take care of the rogue angels, Sam and Dean work normal, everyday cases: dealing with not just demons but also ghosts, monsters (vampires, werewolves, and shapeshifters), gods, and again with angels. They also help out their friend sheriff Jody Mills. However, Dean is suffering from the effects of the Mark and Sam and Castiel desperately try to help him and find a cure, or at the very least, a way to get rid of it, even going as far as to torture Metatron.
Eventually, the Winchesters' friend Charlie returns from Oz as well and after combining her with her alter-ego, which she created from the Wizard of Oz to win the war in Oz, she agrees to help the boys find a cure for the Mark, but Dean is starting to give up and live with it. Hannah eventually abandons her mission with Cas and returns to Heaven. Later on, another one of those threats is the original bearer of the Mark, Cain himself, who has fallen under its influence as well and has started killing his descendants to rid the world of his tainted bloodline, which was stained the moment he killed his brother, Abel. After trapping him in a Devil's trap, Dean and Cain square off in a barn and Dean defeats him, stabbing him with the First Blade, while Sam, Castiel, and Crowley wait for him.
Dean has given up on finding a cure, but Sam still continues to search, going behind Dean's back and convincing Castiel to come see a psychic to contact the boy's surrogate father, Bobby, in Heaven, in order to get Metatron on Earth. After Sam and Castiel remove Metatron's grace, he reveals that he doesn't know how to remove the Mark, but he mentions that Castiel's grace still remains and takes him to it. However, Metatron finds and takes the Demon tablet but not before Cas manages to get his grace back and returns to his status as a Seraph. Sometime after, Charlie contacts the brothers about a possible way to remove the Mark with a book called the Book of the Damned, a very powerful dark magic book that was in possession of the Styne Family, an ancient family that was the inspiration for Mary Shelley's Frankenstein and has consisted entirely of magic practitioners mixed with vastly superior surgical skills for multiple generations.
Sam calls upon Rowena, Castiel, Charlie, and Crowley to read the book and find a way to remove the Mark. However, one of the Styne members kills Charlie and Dean becomes hell-bent on revenge, giving in to the Mark. After the Styne family captures Dean, Dean falls under the Mark's influence, kills the entire Styne family, savagely beats and almost kills Castiel when he tried to stop Dean, and disappears. He heads to a Mexican restaurant and summons Death, the Pale Horseman himself, to kill him. However Death reveals that the Mark not only makes Dean unkillable, thus even he can't kill Dean, he also tells Dean that if he even removes the Mark without passing it along to another host, it will unleash the Darkness, a destructively powerful primordial force that predates the Earth, the Universe, the Archangels, and even God Himself. He also tells Dean that after God and the Archangels fought the Darkness in a horrifying war, God created the Mark of Cain to lock away the Darkness, and sealed it away using the Mark, which was originally borne by Lucifer himself. The Mark revealed itself as a curse after corrupting Lucifer as he became jealous of humans, who was banished to Hell for his crimes against humans and God. Lucifer passed the Mark on to Cain before his imprisonment in his Cage, who then transferred it to Dean.
Death tells Dean that he can send Dean somewhere else so that the Darkness remains sealed and the Mark remains intact on a host, but he has to kill Sam. After Sam and Dean fight, Dean is ready to kill Sam with Death's Scythe, but ironically, Dean kills Death at the last second due to his love for his brother. After that, the Mark is removed from Dean's arm, thanks to the spell from the Book of the Damned cast by Rowena, who later pins Castiel and Crowley and puts Castiel under her attack dog spell so he will kill Crowley. Elsewhere, the Darkness is released.
- Jared Padalecki as Sam Winchester (23/23)
- Jensen Ackles as Dean Winchester (23/23)
- Misha Collins as Castiel (13/23) and Jimmy Novak (1/23)
- Mark A. Sheppard as Crowley (12/23)
- Ruth Connell as Rowena (12/23)
- Erica Carroll as Hannah (4/23) / Caroline Johnson (1/23)
- Travis Aaron Wade as Cole Trenton (4/23)
- Curtis Armstrong as Metatron (4/23)
- Kathryn Love Newton as Claire Novak (3/23)
- Felicia Day as Charlie Bradbury (3/23)
- Raquel Riskin as Dar (2/23)
- Jackson Berlin / Viv Leacock as Gerald (2/23)
- David Nykl as Lester Morris (2/23)
- David Hoflin as Eldon Frankenstein (2/23)
- Emily Fonda as Ann Marie (1/23)
- Brit Sheridan as Kate (1/23)
- Rob Benedict as Chuck Shurley (1/23)
- Brianna Buckmaster as Sheriff Donna Hanscum (1/23)
- Kim Rhodes as Sheriff Jody Mills (1/23)
- Timothy Omundson as Cain (1/23)
- Jim Beaver as Bobby Singer (1/23)
- Ty Olsson as Benny Lafitte (1/23)
- Julian Richings as Death (1/23)
Episode List 2014-2015
|200px||Black||Writer: Jeremy Carver||Director: Robert Singer||10/7/14||#196 1001|
|DEAN IS LIVING IT UP AS A DEMON WHILE SAM HITS ROCK BOTTOM IN THE SEARCH FOR HIS BROTHER — Dean (Jensen Ackles) is a demon and running amuck with Crowley (Mark Sheppard) while Sam (Jared Padalecki) tries to figure out what happened to his brother. Meanwhile, Castiel (Misha Collins) is dealing with his diminishing grace.
|200px||Reichenbach||Writer: Andrew Dabb||Director: Thomas J. Wright||10/14/14||#197 1002|
|CROWLEY TELLS DEAN THE MARK NEEDS TO BE FED — Crowley (Mark Sheppard) notices Dean (Jensen Ackles) is becoming more and more aggressive. Dean tells him that’s the side effect of being a demon, but Crowley knows it’s something more - the Mark of Cain needs to be fed. Meanwhile, Sam (Jared Padalecki) is captured by Cole (guest star Travis Aaron Wade), an angry man who blames Dean for his father’s death years ago and wants revenge. Cole tortures Sam, hoping he’ll tell him where Dean is hiding. Hannah (guest star Erica Carroll) sees how weak Castiel (Misha Collins) is becoming as his grace continues to fade, so she makes a bold choice and asks Metatron (guest star Curtis Armstrong) for help.
|Soul Survivor||Writer: Brad Buckner & Eugenie Ross-Leming||Director: Jensen Ackles||10/21/14||#198 1003|
|JENSEN ACKLES RETURNS TO THE HELM AS DIRECTOR — Sam (Jared Padalecki) continues his efforts to save Dean (Jensen Ackles) from the Mark of Cain. Crowley (Mark Sheppard) realizes Dean’s demonic antics are starting to cause problems for him in Hell so he searches out an unlikely ally – Castiel (Misha Collins). Jensen Ackles directed the episode written by Brad Buckner & Eugenie Ross-Leming.
|200px||Paper Moon||Writer: Adam Glass||Director: Jeannot Szwarc||10/28/14||#199 1004|
|WEREWOLF KATE RETURNS — A recent string of werewolf attacks points to a surprising culprit – Kate (guest star Brit Sheridan), the werewolf Sam (Jared Padalecki) and Dean (Jensen Ackles) let live.
|200px||Fan Fiction||Writer: Robbie Thompson||Director: Phil Sgriccia||11/11/14||#200 1005|
|SUPERNATURAL CELEBRATES ITS 200TH EPISODE — When Sam (Jared Padalecki) and Dean (Jensen Ackles) investigate the disappearance of a teacher, they are stunned to see the school is putting on a musical based on their lives. Familiar faces abound in this milestone episode.
|200px||Ask Jeeves||Writer: Eric Charmelo & Nicole Snyder||Director: John MacCarthy||11/18/14||#201 1006|
|DEAN GETS A SURPRISING MESSAGE FROM BOBBY’S CELL PHONE — Dean (Jensen Ackles) is surprised when he checks Bobby’s cell phone and hears a message that says Bobby or his next of kin have been named as a beneficiary in an heiress’ will. Hoping that means extra money, Dean talks Sam (Jared Padalecki) into hitting the road to claim their fortune. However, what they encounter at the house is far from a treasure chest.
|200px||Girls, Girls, Girls||Writer: Robert Berens||Director: Robert Singer||11/25/14||#202 1007|
|ROWENA REAPPEARS — Sam (Jared Padaleck) and Dean (Jensen Ackles) stumble upon a demon who is running from Crowley (Mark A. Sheppard). Before they have a chance to shut him down, Rowena (guest star Ruth Connell) steps in and takes things into her own hands. Realizing Rowena is trying to recruit and train followers in the art of witchcraft, Sam and Dean come up with a plan to catch her before she can do much damage. Meanwhile, Hannah (guest star Erica Carroll) runs into a blast from her vessel’s past, which complicates things for her and Castiel (Misha Collins).
|200px||Hibbing 911||Writer: Jenny Klein & Phil Sgriccia||Director: Tim Andrew||12/2/14||#203 1008|
|JODY MILLS RETURNS — Jody Mills (guest star Kim Rhodes) reluctantly attends a mandatory sheriff’s retreat and is partnered with an overeager sheriff named Donna (guest star Briana Buckmaster) who wants to bond. Just as Jody thinks things can’t get any worse, a body with just strings of meat and skin hanging off the bones is discovered. While the local sheriffs blame an animal attack, Jody knows better and calls Sam (Jared Padalecki) and Dean (Jensen Ackles).
|200px||The Things We Left Behind||Writer: Andrew Dabb||Director: Guy Bee||12/9/14||#204 1009|
|CASTIEL REUNITES WITH JIMMY’S DAUGHTER CLAIRE — Castiel (Misha Collins) finds Jimmy’s daughter Claire (guest star Kathyrn Love Newton) in a group home and she convinces him to break her out. After she runs away from him, Castiel calls Sam (Jared Padalecki) and Dean (Jensen Ackles) to help find her before she gets in trouble. Meanwhile, Crowley (Mark A. Sheppard) faces his biggest challenge yet.
|The Hunter Games||Writer: Eugenie Ross-Leming & Brad Buckner||Director: John Badham||1/20/15||#205 1010|
|THE AFTERMATH — After the massacre at the ranch, Dean, Sam, and Castiel double their efforts to find a cure for the Mark of Cain but there is nothing in the lore that can help them. Desperate, Castiel comes up with an idea that Sam deems the “single worst idea I’ve ever heard.” Meanwhile, Rowena (guest star Ruth Connell) continues to plot against Crowley, and Castiel tries to mend his relationship with Claire (guest star Kathryn Love Newton) who is plotting revenge against Dean for killing her friend.
|200px||There's No Place Like Home||Writer: Robbie Thompson||Director: Phil Sgriccia||1/27/15||#206 1011|
|CHARLIE RETURNS FROM OZ — Sam is scanning the internet for suspicious paranormal activity and comes across a video of Charlie (guest star Felicia Day) beating up a district attorney. Dean suspects she’s back from Oz and hunting on her own, assuming the district attorney must have been a demon. When they do find Charlie, they are shocked when she tells them why she really came back from Oz.
|200px||About a Boy||Writer: Adam Glass||Director: Serge Ladouceur||2/3/15||#207 1012|
|DEAN IS TURNED INTO HIS 14 YEAR OLD SELF- Looking to get Dean (Jensen Ackles) out of the bunker, Sam (Jared Padalecki) finds a case for him and Dean to investigate- people are disappearing into thin air with only their clothes left behind. Sam and Dean suspect fairies or angels, but the truth turns out to be much more shocking- Hansel (guest star Mark Acheson), from Hansel and Gretel lore, is kidnapping people and turning them into their younger selves to placate the evil witch (guest star Lesley Nicol). Unfortunately, Dean finds this out the hard way after he becomes Hansel's next victim and reverts to his 14 year old self.
|200px||Halt & Catch Fire||Writer: Eric Charmelo & Nicole Snyder||Director: John F. Showalter||2/10/15||#208 1013|
|GHOSTLY CONNECTION — A ghost starts killing people through various electronic devices. Sam and Dean discover who was killed and why this ghost is seeking revenge on a group of college students but what they can’t figure out is how he’s doing it. With three dead, the brothers must stop the ghost before he claims his next victim.
|200px||The Executioner's Song||Writer: Robert Berens||Director: Phil Sgriccia||2/17/15||#209 1014|
|THE RETURN OF CAIN — Dean (Jensen Ackles), Sam (Jared Padalecki) and Castiel (Misha Collins) deal with Cain’s (guest star Timothy Omundson) return. Crowley (Mark Sheppard) and Rowena (guest star Ruth Connell) continue to grow closer but when Crowley bails on plans with his mother to help the Winchesters, Rowena lets him have it.
|200px||The Things They Carried||Writer: Jenny Klein||Director: John Badham||3/18/15||#210 1015|
|COLE PAYS A VISIT TO THE WINCHESTERS — Despite Dean’s (Jensen Ackles) directive to forget about looking for a cure for the Mark of Cain, Sam (Jared Padalecki) continues to do research. Dean suspects Sam is hiding something but decides to focus on a new murder case where they run into Cole (guest star Travis Aaron Wade). The three team up and learn a Khan worm is infecting men and turning them into murderers. Unfortunately, the worm makes it’s way into Cole.
|200px||Paint it Black||Writer: Eugenie Ross-Leming & Brad Buckner||Director: John F. Showalter||3/25/15||#211 1016|
|ROWENA MAKES PLANS TO RECLAIM HER MAGIC — Sam (Jared Padalecki) and Dean (Jensen Ackles) investigate a string of suicides committed by people with little in common other than the identical, grisly method of death – slow, self-administered disembowlment. All of the victims were members of a Catholic church and had recently given confession, leading the brothers to suspect the priest (guest star Stephen Daniel Curtis) is somehow involved. Meanwhile, when Crowley (Mark Sheppard) captures Olivette (guest star Teryl Rothery), the leader of the Grand Coven, Rowena (guest star Ruth Connell) pleads her case to be allowed to practice magic freely again.
|200px||Inside Man||Writer: Andrew Dabb||Director: Rashaad Ernesto Green||4/1/15||#212 1017|
|DEAN AND ROWENA FACE OFF AGAINST EACH OTHER — Sam (Jared Padalecki) and Castiel (Misha Collins) follow up on a lead about the Mark of Cain. Dean (Jensen Ackles) and Rowena (guest star Ruth Connell) meet.
|200px||Book of the Damned||Writer: Robbie Thompson||Director: P.J. Pesce||4/15/15||#213 1018|
|FELICIA DAY RETURNS AS CHARLIE — Charlie (guest star Felicia Day) calls Sam (Jared Padalecki) and Dean (Jensen Ackles) to tell them she found the Book of the Damned which could help remove the Mark of Cain. The Winchesters race to her after she tells them she’s been shot by a man named Jacob Styne (guest star Jeff Branson) who says the book belongs to his family and he won’t rest until he gets it back. Castiel (Misha Collins) and Metatron (guest star Curtis Armstrong) take a road trip to find Castiel’s grace but they hit a couple road bumps along the way.
|200px||The Werther Project||Writer: Robert Berens||Director: Stefan Pleszczynski||4/22/15||#214 1019|
|CAN DEAN SAVE SAM? — Sam (Jared Padalecki) learns that former Men of Letters, Magnus, once built a magical box and Sam sets out to find it in the hopes it can cure Dean (Jensen Ackles) of the Mark of Cain. However, what he’s not prepared for is the deadly alarm system Magnus set up on the box. When Sam opens the box, he puts both his and Dean’s life in danger.
|200px||Angel Heart||Writer: Robbie Thompson||Director: Steve Boyum||4/29/15||#215 1020|
|CLAIRE NOVAK RETURNS — When Claire Novak (guest star Kathryn Love Newton) gets a lead on her mother, Amelia (guest star Leisha Hailey), who has been missing for years, Castiel (Misha Collins) asks Sam (Jared Padalecki) and Dean (Jensen Ackles) to help her. Castiel feels guilty for what he did to the Novak family and wants to make amends by reuniting Claire with her mom. However, when they find out what took Amelia, they realize there is a chance Claire may not get her happy ending.
|200px||Dark Dynasty||Writer: Eugenie Ross-Leming & Brad Buckner||Director: Robert Singer||5/6/15||#216 1021|
|THE WINCHESTERS MEET THE STYNES — Dean (Jensen Ackles) and Sam (Jared Padalecki) investigate a bizarre murder and realize the killer bears the same tattoo as those from the Styne family. Eldon Styne (guest star David Hoflin) attacks Dean and a brutal fight ensues. Meanwhile, Castiel (Misha Collins) acts as referee when Charlie (guest star Felicia Day) and Rowena (guest star Ruth Connell) are forced to work together on the Book of the Damned. Crowley (Mark Sheppard) discovers his mother is missing and knows she’s up to something so he turns to an old enemy for help.
|200px||The Prisoner||Writer: Andrew Dabb||Director: Thomas J. Wright||5/13/15||#217 1022|
|DEAN IS ON A RAMPAGE — When it comes to the Stynes, Dean (Jensen Ackles) decides to take matters into his own hands. Sam (Jared Padalecki) tries to come to terms with his decision.
|200px||Brother's Keeper||Writer: Jeremy Carver||Director: Phil Sgriccia||5/20/15||#218 1023|
|SUPERNATURAL SEASON FINALE — Dean (Jensen Ackles) makes a shocking decision regarding the Mark of Cain that would change not only his life, but Sam’s (Jared Padalecki) too. Meanwhile, Crowley (Mark Sheppard) and Rowena (guest star Ruth Connell) face off and Castiel (Misha Collins) gets caught in the middle.
- Season 10 seems to be the only season in which every episode does not begin with a "Then/Now" sequence.
- The show's 200th episode aired during this season, the 200th episode of the series was the 5th episode of the season and it was a musical themed episode.
- Jensen Ackles directed the 3rd episode of the season. Source.
- Who will be the Big Bad of Supernatural Season 10? –Tom Would you believe it’s… Sam and Dean? As the Winchesters battle their inner demons — literal and figurative — the show “be introducing, over the course of the season, characters that are very, very, very personal to our main characters,” executive producer Jeremy Carver previews, “and that’s all going to start to snowball into, ‘You are who you are,’ and having to deal with all this and drawing some lines. Of course, there’ll be Bigger Bads that emerge, but the central focus of the season is really on these personal arcs.” BONUS SCOOP: Carver reveals, “You will most definitely see Charlie’s (played by Felicia Day) return from Oz.”