Supernatural season 10
Supernatural season 10 cover pictureCW

Supernatural season 10 premiere introduced viewers to Demon Dean (Jensen Ackles) on the road with his new 'friend' Crowley (Mark Sheppard), the king of hell.

The episode 2 is titled Reichenbach, and the official synopsis reads:

"Crowley (Mark Sheppard) notices Dean (Jensen Ackles) is becoming more and more aggressive. Dean tells him that's the side effect of being a demon, but Crowley knows it's something more — the Mark of Cain needs to be fed. Meanwhile, Sam (Jared Padalecki) is captured by Cole (guest star Travis Aaron Wade), an angry man who blames Dean for his father's death years ago and wants revenge. Cole tortures Sam, hoping he'll tell him where Dean is hiding. Hannah (guest star Erica Carroll) sees how weak Castiel (Misha Collins) is becoming as his grace continues to fade, so she makes a bold choice and asks Metatron (guest star Curtis Armstrong) for help."

In the premiere episode Sam (Jared Padalecki) discovered that Dean is not dead, but has become a demon and has teamed up with Crowley. Sam vowed to rescue his brother, but was interrupted by Cole, a hunter with vendetta against Dean, who takes Sam hostage.

Will Dean save Sam from Cole?

Meanwhile, Crowley reveals that for Dean to stay alive (as Demon), he has to feed the Mark of Cain.

Executive producer Jeremy Carver told E! News, "Sam very much has a different mindset and a much stronger desire, and frankly need, to find his brother and make sure that he's OK. That will lead him to do certain things that are maybe not at the time when Sam was doing them as obviously dark as they will be exposed to be when he has to face up to them later."

Although Dean now appears to be a demon in all of his glory, it is difficult for even the show's producer to be unaffected by the character's countless deaths throughout the show.

"There's a lot of drama in it in the idea of Sam having to watch his brother die so many times," Jeremy revealed.

"It wasn't until I watched the episode that it really hit me just how devastating that was. It was like hundreds of thousands of times having to watch this, and that was a pretty heavy one for me to watch."

In the upcoming episodes, viewers should only expect the darkness to deepen. This season is described as a highly "personal" 10th season, and the producer said: "... The fate of our characters is at stake. These people really have to decide who they are and they're going to have to make very big decisions."

Here are a few promotional pictures:

Supernatural season 10 Episode 2
The CW
Supernatural season 10 Episode 2
The CW
Supernatural season 10 Episode 2
The CW
Supernatural season 10 Episode 2
The CW