Dean (Jensen Ackles) and Sam (Jared Padalecki) Winchester have faced what some might say is way more than their fair share of monsters and demons over the course of Supernatural's 13 seasons. But when the CW series returns this October, they'll be up against their toughest foe yet: Michael.

With the archangel in full possession of Dean's body and the real Dean nowhere in sight, the upcoming season will take on a much darker tone as Sam and the rest of the gang search for the elder Winchester. Considering that Michael is hellbent on world domination and the only supernatural beings with enough power to stop him are out of commission — Jack (Alexander Calvert) has lost his powers and Lucifer (Mark Pellegrino) is dead — that probably won't be easy.

"It's gonna be interesting, because this angel comes with quite a sordid past. He's done some things, and he's also going to do things while wearing the Dean meat suit, so to speak," Jensen Ackles tells TV Guide. "But I think the real question is: How aware is Dean while riding shotgun, essentially, to Michael? And how is that going to affect Dean once [he] gets back?"

When Dean does eventually return — come on, you know it's happening — Michael's actions will not be quickly forgotten. As Ackles notes, the effects of Michael's possession will continue to weigh on Dean, playing out over the course of the season's remaining episodes, however many that will be. But with Dean MIA, it's initially going to be up to Sam to lead the fight against Michael and other evil-doers walking about. However, between stepping up as a solo leader, worrying about his brother and tackling the regular mix of demons, Sam will find himself understandably overwhelmed.

"I think Sam is terrified. Sam's been possessed by Lucifer and he knows the power that an archangel possesses," Jared Padalecki explains. "To complicate it, he also has a bunch of Apocalypse World hunters living in the middle of this bunker that he has to be in charge of. On top of all of that, there are still monsters in the real world. He still has other day-to-day tasks, so Sam is just terrified. He just loves his brother; he worries about him and now he doesn't have his main confidant to help him make decisions."

According to executive producer Eugenie Ross-Leming, Sam's new solo mission will actually be the perfect opportunity for growth, since he'll be forced to fend for himself in such dire times.

"He grows into the part of the leading brother and organizing and doing all the stuff he would share with Dean ordinarily," says Ross-Leming. "It's sort of an exercise in separation and maturity. They both have to mature separately from one another."

Season 14 certainly seems like a good time to finally make that leap, no?

Supernatural returns for Season 14 on Thursday, Oct. 11 at 8/7c on The CW.

(Full disclosure: TV Guide is owned by CBS, a parent company of The CW.)