'The Vampire Diaries' season 8 episode 8 spoilers: Damon and Stefan to work together as Cade's new loyal servants?

Tougher and darker times are ahead for immortal brothers Damon (Ian Somerhalder) and Stefan (Paul Wesley) when the eighth season of "The Vampire Diaries" returns in January for episode 8.

In the supernatural series' mid-season finale titled "The Next Time I Hurt Somebody, It Could Be You," it can be recalled that Stefan met with Cade (Wole Parks) following his ruined Christmas dinner with Caroline (Candice King). He made a deal for the safety of Caroline's twins, in which he would turn off his humanity in order to feed more souls to Cade. However, in exchange, their contract must be shortened to a year. Episode 7 concluded with the brothers Stefan and Damon leaving Mystic Falls with Stefan turning off his humanity.

Based on the promotional preview for season 8 episode 8, it looks like Damon and Stefan will take an even darker path, becoming Cade's new loyal servants. And it looks like escaping from Cade's grasp won't be an easy task.

"I'm working for the devil; I don't need to play fair," Stefan is seen saying in the preview, with Damon attacking a group of people.

On the other hand, it looks like Stefan and Caroline's romance will be taking a beating in the upcoming episode. The situation they find themselves could lead to serious misunderstandings between the couple. If there is a chance to salvage their relationship, Stefan will have to come clean with his deal with Cade before it's too late.

The threat that may break-up the "Steroline" team-up may be a cause of concern for the fans of the match-up, especially following Wesley's statement in an interview with TV Line.

Speaking about the probable conclusion to the story of Stefan and Caroline's relationship, Wesley said, "I certainly don't think they should live happily ever after, but it's a nice distraction from the reality of ... all the atrocities Stefan has committed throughout the years."

"The Vampire Diaries" season 8 episode 8 is scheduled to air next year on Friday, Jan. 13, at 8 p.m. ET on The CW.