|Episode(s)|| 14.07 Unhuman Nature|
15.07 Last Call
As for my curriculum vitae, I am passionately peripatetic. No roots. I've re-crossed the globe many many times over. Studying and observing the skills of myriad witches, and seers, holy men, et cetera.
– Sergei, 14.07 Unhuman Nature
Sergei is a Russian shaman who used to consult for the British Men of Letters when they would come across an unsolvable problem. Sergei prefers not to have roots, claiming to have crossed the globe many times over to study and observe the skills of myriad witches, seers, and holy men. As a shaman, Sergei tries to "answer the unanswerable" and "know the unknowable" but considers himself first and foremost a healer.
He has a niece named Anna who was recently admitted to USC on a rolling scholarship. Castiel had Bobby keep an eye on her in order to hold leverage over Sergei.
After speaking with Ketch about Jack's situation, Sam is directed to Sergei, a shaman that the British Men of Letters have sworn by to help "solve the unsolvable" in the past. While Dean takes Jack out for a bit, Castiel decides to take the meeting Ketch has set up, and drives out to meet with Sergei.
Arriving in a wooded area, Castiel begins walking to a trailer only to be stopped by a ring of holy fire. Sergei steps outside, shotgun in hand, and asks if Castiel brought anyone else with him. Once he is sure Castiel is alone, he invites him inside for some tea. Sergei give Castiel his "curriculum vitae", explaining his qualifications before moving onto the subject of Jack. He tells Castiel he does not believe Jack's condition can be reversed, but his system can be shocked to stop the progression. When Castiel asks how they could possibly achieve that, Sergei produces a vial of archangel grace which he says is from Gabriel, explaining that he bartered a cloaking spell which allowed Gabriel to hide away in Monte Carlo for it. Handing it over to Castiel, he tells him they will need to recite a specific spell, then hands him the box which contains it. Castiel questions what the cost would be, but Sergei tells him his services are for barter only, and to tell the Winchesters that they "owe [him]."
After administering the grace to Jack to no avail, Castiel places a call to Sergei demanding his help, as Jack's condition has worsened. A disinterested Sergei explains that science is "trial and error." As Castiel threatens to find him if Jack dies, Sergei simply chuckles and dares him to try.
With Sam in bad shape, Castiel places a call to Sergei, claiming that due to what happened with Jack, Sergei owes him. Sergei tells Castiel he is busy taking his niece shopping, but Castiel does not take his no for an answer, and threatens to find Sergei and burn him alive if he doesn't help.
Sergei arrives at the Bunker, in awe of being in the fabled home of the Men of Letters. Castiel leads Sergei to the infirmary, where Eileen is tending to a still-unconscious Sam, and pleads for him to help Sam. Sergei obliges, producing a crystal from his satchel and waving it over Sam's body until it begins to light up when it reaches Sam's bullet wound. He instantly realizes what is wrong -- Sam is dying.
In the Bunker's library, Sergei explains that Sam's wound is connected to his soul and also tethered to someone or something in the outside world. After treating Sam's wound, Sam's condition becomes worse. In the hallway, Sergei tells Castiel and Eileen that in exchange for receiving the Key to Death in the Bunker, he will reverse what he has done to Sam. Eileen and Castiel refuse, and Castiel shows Sergei a photo of his niece, Anna, whom he has Bobby Singer keeping an eye on, and threatens to have her harmed if Sergei doesn't fix Sam. Sergei agrees and performs a ritual that wakes Sam up. Upon leaving, Sergei remarks that he likes the new Castiel, telling him he is very... Russian.
Castiel calls Sergei for help to find a way to open a rift without archangel grace, however he is ignoring his calls.