WARNING: The following article contains spoilers for Season 15, Episode 6 of Supernatural, "Golden Time."
Following last week's thorough smackdown at the hands of a newly resurrected Lilith by Chuck, the Winchesters really needed a win this week. Luckily for them, that's exactly what they got, in the form of a deceased hunter making her way back into their lives: Eileen Leahy.
Introduced in Season 11, Eileen was turned onto hunting following the loss of her parents to a Banshee in her native home of Ireland. She also lost her hearing during the traumatizing incident, but a fire was lit under her to seek revenge. This path took her all the way to Kansas, where she crossed paths with Sam and Dean and the trio struck up a friendship; the brothers even started learning sign language to better communicate with her. Unfortunately, like many a Winchester ally, Eileen met a nasty end in Season 12 thanks to a Hellhound under the command of Arthur Ketch.
She first appears to Sam in Season 15 as a faint shimmer in the air, before fully materializing as a ghost. Though the Winchesters assumed she must have gone to Heaven when she died, Eileen tells them, glumly, that the Hellhound dragged her to Hell; she then became one of the recently released spirits when Chuck breached the underworld's barrier. As Kevin Tran's ghost told them at the start of this season, the escaped spirits from Hell now have two (not so great) choices: either go mad wandering Earth for the rest of eternity or return to Hell, which is... Hell. Eileen wants to go to Heaven where she belongs but Dean shoots her wish down, pointing out that Heaven doesn't accept souls that have been sent down below.
Instead, he suggests that they create a private Soul Catcher for Eileen to rest in, sending Sam off to Rowena's apartment to fetch the necessary magical ingredients. Sam is reluctant to go there as he's still reeling from Rowena's loss, and it doesn't help that he was responsible for this loss, either. His urge to ease Eileen's horrible situation spurs him on though. It's just as well, too, because while searching through the witch's secret stash of magical items and journals, the younger Winchester brother stumbles across an even better solution: the spell that Rowena had been working on to reunite Mary Winchester's soul with her body.
With Mary safely at peace in Heaven, Sam decides not to let the powerful spell go to waste; using it on Eileen instead. Pulling this off becomes a little more complicated when a group of thieving witches shows up to raid Rowena's wares, the older of which notes that Sam is the only one immune to the anti-intruder hex Rowena placed on the apartment. In essence, this as good as the ancient witch making Sam the sole inheritor of all her possessions.
A fight soon breaks out when Dean arrives to back his brother up: Dean brings the witch-killing bullets; Sam whips up a hex bag and Eileen has a ghost vs. ghost tussal with a witch who fell foul of Rowena's magic security alarm. Later on, Sam is finally able to finish off the single-use resurrection spell that Rowena started, bringing Eileen back into the world of flesh and blood once more.
It's a touching moment seeing Eileen recover from her premature death and Sam find a way to honor Rowena's memory by embracing the things she bequeathed him: not just her arsenal of magical items and knowledge, but also his true calling as her protege.
Airing Thursdays at 8 p.m. ET/PT on The CW, the final season of Supernatural stars Jensen Ackles, Jared Padalecki, Misha Collins and Alexander Calvert.