When the hugely-popular The Vampire Diaries returns next year, the series will take its characters into a darker future, says producer Julie Plec.

"We're going to come to the end of what we're calling our werewolf chapter, which will take that story to a really dark place and really change a lot of characters' lives, not necessarily in a good way," Plec told ShowbizSpy.

The series went into a hiatus this month, but it did cue in fans what's in store for them next year. Ian Somerhalder's Damon discovered that a bite from a werewolf is actually fatal to vampire, after Rose gets rashes after her encounter with one.

Plec said: "We are going to dig deeper into the secrets of our new witches and what Bonnie's role is going to be in their story, and of course it's all about the fear of the impending Klaus..."

"[Who is] going to be fighting on who's side, whose bond is with who, who's going to betray whom, and is this curse going to be lifted at the hands of a sacrifice that would kill Elena? We're full steam ahead."

What's certain with this development is that Michael Trevino's character, the werewolf Tyler Lockwood will come at the fore in the series as The Vampire Diaries takes on its "werewolf chapter." The series returns on January 27th at 8pm on the CW.