From Amara to Chuck, there's trouble in the air on Supernatural.

Sam (Jared Padalecki) and Dean (Jensen Ackles) have battled the Darkness (Emily Swallow) all season long, but to no avail. The only real win the Winchesters scored over their divine nemesis came in "Form and Void" when Sam defeated Amara's disturbing black-vein afterbirth. In "Don't Call Me Shurley," that victory will be wiped off the board.

The Darkness will plague yet another town with her own special form of rage monsters during episode 20, but this time the hunters' cure will no longer work. There may be a light at the end of the tunnel, however. Chuck (Rob Benedict) is back, and he has a proposal for the Winchesters.

Whether it's from excitement, horror, or shock, tonight's episode will make you scream.

At least Benedict will be on hand to help elucidate Chuck's sudden return. After vanishing into thin air six seasons ago, the writer/prophet/potential deity popped up once in season 10 but hasn't been seen since. Will Supernatural finally reveal his true identity? Fans are sure to have questions, and you can find out what Benedict has to say when he jumps on Twitter to live tweet the ep.

Are you excited for "Don't Call Me Shurley"? Check out the episode summary below:

"Amara unleashes a dark fog on a small town, causing everyone to go mad. Dean and Sam realize this is a stronger version of the original black vein virus Amara previously unleashed. They team up with the sheriff to protect the town but their old remedy no longer works," The CW teased. "Meanwhile, Chuck returns with an interesting proposal."

Catch Supernatural Wednesdays at 9 p.m. ET on The CW.

Tags: supernatural television the cw