The season 10 finale of "Supernatural" saw the Winchester brothers' terrifying encounter with the Darkness, and in the new season, Dean (Jensen Ackles) and Sam (Jared Padalecki) will continue to fight what might be their biggest and most mysterious foe to date. The two will also try to figure out what the Darkness is, since very little is known about it.

At the San Diego Comic-Con last July, executive producer Andrew Carver said that fans will get a general idea of what the Darkness is capable of "within the first 20 seconds" of the premiere. In season 10, Death told the brothers that the Darkness is an evil force that God defeated and locked away during pre-Biblical times, and Dean and Sam have to figure out how to defeat it. 

Speaking to Entertainment Weekly, Ackles said that the brothers are not sure what the new evil force is capable of. Moreover, they don't have the faintest idea about it. 

"This one's interesting because it's not really a monster," said the actor. "It's more of a primal force that we know nothing about. There's no lore; no guidebook; there's no instruction manual on how to deal with this." 

But one thing that will surely help their cause is that this time around, Sam and Dean will be fighting the same enemy together. In previous seasons, the two were battling each other for different reasons, such as in season 10 when Dean turned evil due to the Mark of Cain and Sam had to stop him from doing harm. In season 11, the show is going back to its roots by showing the two working together against a common foe. 

Ackles told TVLine that he's happy with the brothers' united front this season, and that one of the things that he likes about the season 11 storyline is it's going back to the original format of both brothers being unaffected by evil forces.

"[It's] just Sam and Dean as Sam and Dean, fighting a common target," Ackles told the website.

"Supernatural" season 11 premieres on Oct. 7 at 9 p.m. on The CW.