Lucifer's mindgames with Sam finally push him over the edge and, after being hit by a car, Sam is sectioned in a psychiatric ward.
Dean desperately searches for a cure to Sam's condition and seems to be getting nowhere trawling through all of Bobby's old contacts when he learns of a faith healer called Emmanuel.
Going to investigate, Dean discovers that demons are also after this Emmanuel... and Emmanuel turns out to be Castiel, but stricken with severe amnesia after the events at the start of this season.
Dean is determined to get "Emmanuel" to the hospital to cure Sam, but his path is dogged by demons. Then Meg (Rachel Miner) - last seen in Season Six's Caged Heat - shows up and offers to help Dean (towards her own ends, of course).
Meanwhile at the hospital, Sam finds time to help a fellow patient (Kacey Rohl) lay to rest the ghost of her brother who has been driving her towards suicide.
Written by showrunner Sera Gamble and directed by Robert Singer, and featuring the return of Misha Collins, The Born-Again Identity was always going to be a strong episode but it took the sub-plot of Sam's "delusions" into areas I wasn't expecting, especially with its humdinger of a double-barrelled final twist.
That said, I realise the mini-plot of Marin (Kacey Rohl) and her ghostly brother (Kai James) was there to give Sam something proactive to do instead of simply trying to ignore Lucifer's taunts and battle his psychosis, but it felt a bit random, a bit shoehorned in to the episode.
With so much going on with Dean, Cas and Meg, this ghostly interlude was almost a wafer-thin mint too much on top of an already filling meal.
But the main thing to take away from this episode is that we now know that Cas is back in the game...