The Winchester brothers are back to save the world from a new threat called Darkness in Supernatural's season 11 premiere. That's not all - Castiel battles the dog spell cast by Rowena which compels him to kill Crowley. Episode 1 is titled Out Of The Darkness, Into The Fire, which will air this Wednesday 7 October at 9pm EST on The CW Network.

The official synopsis for the episode reads as follows:

Picking up where the finale left off, Sam (Jared Padalecki) and Dean (Jensen Ackles) must deal with the Darkness that has been unleashed. Castiel (Misha Collins) deals with the effects of Rowena's (Ruth Connell) spell and recalls his brutal battle with Crowley (Mark A. Sheppard). Robert Singer directed the episode written by Jeremy Carver.

Click here to watch the episode online on the official CW website.

The season 10 finale left off with Dean and Sam hiding in their impala as Darkness takes over. More details about what this new threat is and what it entails will be revealed in the upcoming episodes.

Executive producer Jeremy Carver teased that the first two episodes will be shown as a big mystery story. "One things fans might want to do is take a look at episode one and two of season 11 as one big story, basically one big mystery centering around what is Darkness and what does the Darkness wants," Carver said in a promo video.

This season will also reunite the three lead characters, Sam, Dean and Castiel. Misha Collins (Castiel) said his character and Dean will put their differences aside and unite to fight the pre-Biblical threat. "We are going to see them put their differences aside and unite against that common enemy. I think that they are aware that the presence of The Darkness is actually their fault and they have to clean up the mess that they have made.

"This season is going to be about reuniting us against a big bad, which is something we have done before, but it is changing it up. It's giving us a new focus and I think that is going to be great," Collins teased.

A new promo hints at difficult times ahead for the Winchester brothers and the Angel as we see scenes of mass destruction and violence. Rowena says, "What new hell has Dean Winchester unleashed upon the world?"