The Secret Circle: Gale Harold Teases "A Lot of Pain" Ahead for Charles and Diana

The Secret Circle got its Jerry Springer on last week when the CW dropped a bombshell on its viewers: Diana ( Shelley Hennig) is Cassie's ( Britt Robertson) half-sister, meaning her real father is not Charles, but John Blackwell ( Joe Lando).

While we've seen Charles do a lot of terrible things, his one redeeming quality has always been his love for his daughter, so it's safe to say things are about to get really juicy in Chance Harbor.

We chatted with Harold about what's next for Charles and Diana's relationship, the long-awaited Blackwell-Charles face-off and what fans can expect from the finale!

"A lot of pain," Harold teases of what's in store for Charles and Diana post-Blackwell reveal. "A lot of pain and suspicion. There's deep suspicion and betrayal. It's like a combination of betrayal and pain. And there's not really anything Charles can do about it. And it's kind of his fault as well. Yeah, it's bad."

Also bad is what this means for Blackwell and Charles' already strained (to put it lightly) dynamic, with Charles trying to kill Blackwell and everything in the last episode. Harold says fans shouldn't expect Charles to give up so easily. " I can tell you that Charles basically has to either edge him out or get rid of him...the face-off, it's not really like a schoolyard fight, it's more like—there is a wildcat stuck in your basement, you got to deal with it. You can't tell your kids that there's a wildcat in your basement because they'd freak out."

While the circle's hunt for the crystals, the very same ones Charles and Dawn (Natasha Hendstridge) have been relentlessly pursuing all season, may become problematic for him, Harold says Charles has a bigger threat looming. "What I think is more dangerous for Charles right now with Blackwell is that he has no idea what Blackwell knows," he explains. "Whatever Blackwell knows is upper hand. And how he uses it determines—he's in a very controlling position. Charles kind of has his hands tied. There's really not much he can do. He has to react."

Considering the show has proven time and time again it's not afraid to off its characters (Nick, Lee, Grandma Jane, take your pick!), Harold says fans should prepare themselves for the finale, which he says contains "a lot of danger." So who exactly is in danger? "They are all in danger, the whole town. Everyone that's involved in this crew, in this witch ghetto, could get eradicated," Harold hints. "There's a lot of crashed cars." Buckle up, kids!

Viewers have seen many different sides of Charles since being introduced as the murderer of Cassie's mother in the pilot, and we were curious to hear Harold's thoughts on the journey his character has taken throughout the season. "The most interesting thing for me is Charles having to sort his way through very realistic problems. Like the problems everyone has to deal with. The fact his wife is dead, he killed two people and his daughter is a witch," Harold says. "There's so much conceptually to make it strange and bizarre, it's more like family stuff, the psychological stuff, Charles slowly going more and more into an unstable place. I'm up for that anytime."

As for what else he would like to see happen with his character? A face-off between Charles and Diana! "I would like for Charles and Diana to have some sort of serious problem that they may have to fight over in more than just an argument," he says. "That they might actually have to battle one another, which I think would be really horrible for a father and daughter, but unavoidable. That's what I would like." Sounds like Harold may just get his wish!