‘Supernatural’ EP Spoilers: Complicated Alliance Between Dean & Sam & The British Men Of Letters? Brothers Fighting Two-Front War, More In Season 12

Dean (Jensen Ackles) and Sam (Jared Padalecki) will face plenty of changes when "Supernatural" returns for its 12^th season this week. The boys' mother Mary (Samantha Smith) has risen from the grave thanks to Amara/The Darkness (Emily Swallow). Mary's return, however, isn't all sunshine and rainbows and the Winchester family have plenty of adjusting to do.

"Supernatural" executive producer Andrew Dabb revealed that Dean and Sam will both be "happy and conflicted" regarding Mary's return, TVLine reported. The brothers are worried about how their mother will "adjust [to] not only the modern world and technology and that kind of stuff but [also] to them and their lives, and [wondering] if she will be what they have become," Dabb added.

Mary didn't interact with angels, demons, and the Men of Letters back when she was still alive as a hunter. She will be shocked when she meets Castiel (Misha Collins) for the first time and it will be a huge adjustment for her.

Mary heard vague tales about the Men of Letters but they never really interacted with the American group of hunters. "So to find out they're real, to find out John has a history with them, to walk into the bunker and see this cache of things she never knew existed, it is a shock to her," Dabb continued.

"Supernatural" Season 12 will also find Dean and Sam "pulled in two different directions" concerning the British Men of Letters and Lucifer, who now has a new vessel in the form of rock star Vince Vincente (Rick Springfield). The world of the British Men of Letters will be explored deeper in upcoming "Supernatural" episodes and viewers will find out that its members aren't all bad. There are times when Dean and Sam will be in alliance with the group and sometimes "they'll be working against them."

In the premiere episode of "Supernatural" Season 12," viewers will see a Castiel driven to find Sam, who has been kidnapped by Lady Toni Bevell (Elizabeth Blackmore), and exact revenge on Lucifer. More of Castiel's personal stories will be tackled but at the same time, Season 12 will feature him side-by-side with Dean and Sam, as always. The angel will also establish a special connection with Mary that stemmed from the fact that they're both outsiders.

"Supernatural" returns for its 12^th season on Thursday, Oct. 13 at 9 PM ET on The CW. Watch the promo for the premiere episode titled "Keep Calm and Carry On" below.