The Big Empty

The Big Empty is the 4th episode of Season 13. It aired on November 2, 2017.

Summary
When multiple patients of grief counselor Mia Vallens (guest star Rukiya Bernard) turn up dead, Sam, Dean and Jack investigate the mystery surrounding the murders and, each inadvertently, are forced to deal with unresolved grief of their own.

Plot
In Wisconsin, a man returns home and is greeted by his wife; who he is shocked to see as she is dead. They exchange pleasantries before she kills him by stabbing him in his abdomen.

At the bunker, Sam arrives with coffee and snacks as Dean is investigating the situation in Wisconsin as some are saying break in, a neighbor claims that sit victim's dead wife. The Winchesters decide to check it out with Sam wanting to take Jack with them as Dean is adamant in refusing but Sam tells him to give the boy a chance. La Scimmia goes on by stating that Sam needs to move on from the pain of losing their mother as Sam calls him out on his cold behavior. He then goes to get Jack who is watching videos and invites him to join in on the recent assignment. Jack refuses and states he knows Sam is trying to get him to use his powers again to open a portal as Sam reveals his reason. He also promises not to allow Dean to hurt him as they go off to their quest.

The trio go to the victim's house where they put on their aliases as FBI and ask the neighbor about what she saw and she explains it was definitely her old neighbor's wife. Dean and Sam begin making deductions on what could of it done it as they decide to visit the dead woman's grave. They burn the body to ensure it's not a zombie and tell a curious Jack they did so for his mother and continue to ponder on what did it.

Meanwhile, in The Empty, Castiel starts calling out for someone to answer where he is. He soon wanders through the Dark realm as a mysterious figure materializes from the ground in a surge of tar-like substance, and follows him.

On Earth, a woman has car trouble and calls for assistance as she turns to see a young boy in her car recognizing him as Scotty who she is happy to see before he kills her. The next day, Dean and Sam are called in and connect the incident with that of the dead wife as they were too similar. The brothers soon see that both victims were seeing a grief counselor named Mia Vallens and thinking she may know something they go check it out.

They pretend to be a trio of brothers who lost their mother. When Dean and Sam have a falling out, Sam steps out as she continues to talk with Dean who is more than less doubtful of therapy. Sam then returns and holds her at gunpoint revealing he discovered Mia is a Shapeshifter as Dean joins him in pointing a gun.

Mia states she did not hurt anyone as the brothers tell her that some of her patients have ended up dead which surprises her. Knowing they are hunters, Mia proclaims her innocence and tells them she has an alibi and to check it out to confirm it.

Dean goes to do so and returns confirming she is telling the truth, to her relief. They then ask if she isn't killing anyone who was as she deduces it to be her old lover Buddy who is also a shifter that enjoyed killing just to torment others. However, she is trying to atone for her past by helping people get through their grief. Understanding, the Winchesters state if Buddy is doing so then he must be taking on the forms of her patients to get information and kill them.

In the other realm, Castiel continues wandering until he feels the presence of the being and tells them to come out as the figure does so by taking on his form. The being introduces itself as a "friendly neighborhood Cosmic Entity" who states it took on his form so he wouldn't be afraid. Castiel questions where he is and the entity explains it is The Empty, the place where angels and demons are sent after death where they are put in eternal slumber. Because of that, the entity was able to sleep though he questions why Castiel is awake and states he has awoken it from its slumber. The entity brings this up to him, as he states nobody has ever awoken but Castiel doesn't know and suggested that the Winchesters must have made a deal, but the entity stated that's not the case as only it has power over the Empty with not even God having power there. It soon probes Castiel through his memories in an attempt to find out what could've woken up Castiel.

While Dean and Jack go to a possible lead, Sam goes through her surveillance cameras to see which one of her patients is the shifter due to shifters eyes flaring on camera. He asks about her sessions and how patients react to which she stated they don't mind as they get out their pain. Sam soon finds the shifter and leaves in Mia's car to pursue them.

In the Empty, the entity explains to Castiel, who remains in pain, what he did and that he wants Castiel back to sleep. Castiel realizes from the entity's description that having him awake is painful for him which the entity confirms, stating that if Castiel can't sleep, it can't sleep. The entity insists that it likes and needs sleep, causing Castiel to suggest that it get rid of him by sending him back to Earth. The entity suggests that it instead throw Castiel so deep into the Empty that he can't bother it anymore, but Castiel recognizes that the entity is bluffing and that it won't work as the entity would've already done it if it would work. The entity acknowledges that Castiel is right, but refuses to send him back, telling Castiel that "it's not part of the deal" and he doesn't want to return. Castiel denies this as his friend need him but The entity states that it has gone through all of Castiel's mind and knows everything there is to know about him and claims that there is nothing back on Earth for Castiel.

Dean and Jack return while Dean calls Sam, Jack speaks with Mia he tells her that he is not actually Sam and Dean's brother and that his mother actually died when he was born. He shows her the video of his mother asking if she will take on her form for him to gain some closure.

Seeing his pain, she does so and Jack hugs "his mother" getting some of his pain out. "Dean" then talks with Sam and the latter announces he's coming back as his brother states he'll be waiting. "Dean" then notes on "fricking easy" it was to get Sam to come back as it turns out to be the shifter while the real Dean is unconscious on the floor. "Dean" barges in and knocks out Jack before holding Mia at gunpoint and reveals himself to be Buddy.

Buddy ties up Dean and Jack while speaking to Mia, being angry she abandoned him to start a new life. He proclaims his intention of destroying that life by having her kill the hostages but she refuses and tells him to kill her.

Just as he's about to shoot, Buddy sees Sam return and readies to kill him by tricking him into coming to him. When Sam starts to open the door, Mia tries to stop Buddy but is pushed aside though Jack uses his power to cause the bullet to ricochet into the wall. This saves and allows Sam to shoot Buddy, killing him.

The entity grasps Castiel's head and painfully shows Castiel visions of his grace being stolen by Metatron, his death at the hands of Lucifer, the Escape of the Leviathans and him returning the souls to Purgatory. The entity then beats Castiel, attempting to convince Castiel to return to sleep by deeming him worthless. However, Castiel refuses the entity's demands and declares that no matter what the entity does, he will fight it for eternity if he is not released. The entity angrily denies Castiel's demands as Castiel continues to demand his release from the realm.

On Earth, Mia apologizes for the trouble she has caused and promised to do something about Buddy. She laments that all her attempts to help people were for naught but Jack states she helped him in his time of need. This somewhat relieves her spirits as she smiled at him in thanks.

At the bunker, Dean meets Jack and congratulates him on his actions in the mission as Jack accepts it. Dean goes to talk to Sam and apologizes for his recent behavior and tells Sam to maintain his faith in bringing back their mother, after the latter starts to doubt his thoughts.

Elsewhere, Castiel awakens somewhere in a meadow and realizes that the entity has resurrected him just as he demanded. Castiel then basks in the sunlight, happy at returning to life.

Main Cast

 * Jared Padalecki as Sam Winchester
 * Jensen Ackles as Dean Winchester and Buddy
 * Misha Collins as Castiel and Cosmic Entity
 * Alexander Calvert as Jack

Guest Stars

 * Courtney Ford as Kelly Kline

Co-Stars

 * Rukiya Bernard as Mia Vallens
 * John Emmet Tracy as Tom
 * Niall Matter as Buddy
 * Matt Hamilton as Wes Bailey
 * Kayla Deorksen as Erica Bailey
 * Brenda Matthews as Gloria Simon
 * Brandy Le as John Driscoll
 * Brenden Sunderland as Scotty / Ghostly Boy
 * Janet Glassford as Bailey's neighbor
 * Alan Silverman as Roadside Assistant (voice only)

Featured Supernatural Beings

 * Nephilim (Jack)
 * Primordial Entities (God, The Darkness; mentioned only, Cosmic Entity)
 * Archangel (Lucifer; mentioned only)
 * Revenant (mentioned only)
 * Seraphim (Castiel)
 * Shapeshifter (Mia Vallens' mother; mentioned only, Buddy, Mia Vallens)

Continuity

 * A shapeshifter was previously featured in the Season 12 episode, There's Something About Mary.
 * Castiel was previously on Earth in the Season 12 episode, All Along the Watchtower.
 * A Practitioner's Guide to Exorcism was previously featured in the Season 10 episode, The Prisoner.
 * The EMF meter was previously featured in the Season 12 episode, Family Feud.
 * In an attempt to get Castiel back to sleep, the Cosmic Entity shows him visions of him returning the souls to Purgatory in Meet the New Boss (Season 7), the Escape of the Leviathans in Hello, Cruel World (Season 7), his grace being stolen by Metatron in Sacrifice (Season 8) and Lucifer killing him in All Along the Watchtower (Season 12).

Trivia

 * The episode was watched by 1.82 million viewers and got a 0.6 rating.
 * The episode aired on November 2, 2017, the 34th anniversary of Mary Winchester's death.
 * This is the first episode where Misha Collins plays multiple characters in an episode since We Happy Few in Season 11.
 * This is the fourth time a character faces another version of their character in the same scene with Dream A Little Dream Of Me in Season 3, The End in Season 5 and The Man Who Knew Too Much in Season 6 being the first three.
 * This is the second episode God does not have anything to do with Castiel's resurrection with I'm No Angel in Season 9 being the first one and is his fifth resurrection overall.
 * It is revealed in this episode that every deceased angel and demon goes to an eternal slumber in The Empty.
 * This is the second episode featuring Dean being impersonated by a shapeshifter. The first was the Serial Killer Shapeshifter in season 1's Skin, the first episode to feature a shapeshifter.
 * Dean often refers to Jack as "The Antichrist" because he believes he is inherently evil due to being the son of Lucifer, however Dean has met the actual Antichrist Jesse Turner, in Season 5 episode I Believe the Children Are Our Future. In the episode Jesse turns out to not be evil at all, and eventually disappears to never be seen again in order to stop anyone being hurt by his powers.
 * Sam approved Jack's dislike against Anakin Skywalker. In the Star Wars Saga, Anakin Skywalker is a Jedi Knight who falls under the influence of the Sith Lord Darth Sidious and turns to the Dark Side of the Force, becoming Darth Vader.
 * When discussing Mary at the beginning of the episode, Dean tells Sam that Lucifer ripped her heart out. This is ironic, considering Lucifer previously saved her life by doing that to another hunter.
 * Sam and Dean initially suspected Mia Vallens could be a medium summoning ghosts to kill people. It's ironic considering Mia's actress, Rukiya Bernard, played a psychic killed by a ghost in the episode The Mentalists.
 * The quote, "It doesn't matter what you are, it only matters what you do." that Mia Vallens says to Jack is word-for-word the exact same thing Sam Winchester tells Jack Montgomery in the Season 4 episode, Metamorphosis.

Errors

 * At the beginning of the episode Jack is watching Star Wars: The Clone Wars TV series, and states that he likes a character called "Osaka", mispronouncing "Ahsoka".

Quotes
"I'm already saved."

- Castiel to Cosmic Entity

"Jack, it doesn't matter what you are. It matters what you do."

- Kelly Kline to Jack

"Oh save it. I have tiptoed through all your little tulips - your memories, your little feelings, yes. I know what you hate, I know who you love, what you fear. There is nothing for you back down."

- Cosmic Entity to Castiel

"Cosmic Entity: Before God and Amara, creation, destruction, Heaven, Hell, your precious little Earth, what was there? Castiel: Nothing. Cosmic Entity: Yes. That's right. Nothing. Nothing but empty and you are soaking in it. Angels and demons, you all come here when you die (...) sleeping an endless, peaceful sleep."

- Cosmic Entity and Castiel talking about The Empty