After being sidelined for nearly the entire second half of “Teen Wolf’s” fifth season, the Dread Doctors are back in action as the villains to beat with a side-helping of Sebastien Valet (Gilles Marini), the man behind The Beast.

Corey (Michael Johnston) might have kept Mason (Khylin Rhambo) hidden from Scott (Tyler Posey) by escaping into the sewers, but there’s nothing that can hide him from the Dread Doctors and their frequency powers.

With Mason kidnapped and no clue where to find him, Scott decides to team up with the last person on earth who he ever thought could be an ally: Theo (Cody Christian).

RELATED: ‘Teen Wolf’: The Beast of Beacon Hills rises and Mason falls

In case anyone was thinking about trusting Theo this time around, let’s not forget that he murdered his own minion minutes before teaming up with Scott and Liam (Dylan Sprayberry) to find Mason, so he doesn’t quite have a heart of gold yet.

He does, however, have the special ability to understand the Dread Doctors, and for the first time all season, so do we. Hearing these immortal villains finally speaking English must have demystified them somehow because after angering Mason by attacking Liam, Mason transforms into The Beast to protect his friend.

Unfortunately, that transformation reminds him of the man he used to be, Sebastien Valet, which means Mason is no more.

RELATED: ‘Teen Wolf’s’ Gilles Marini says the Beast is based on a true story

At this point, we’ve got confirmation that at least one Dread Doctor is dead, unless they can recover from decapitation, and possibly all three met their ends. That would be a little anti-climactic after watching them hover menacingly in the background for the past 19 episodes, so let’s hold out hope that their story is not quite over yet.

As we ramp up to next week’s finale — and a full moon to boot — there are so many questions left to be answered. Will Theo kill The Beast, and Mason by extension? Will the Desert Wolf actually kill Malia? What about that Stydia moment in the previews for next week?

“Teen Wolf” airs Tuesdays at 9 p.m. ET/PT on MTV

Posted by:Lindsay MacDonald

Lindsay MacDonald is a Los Angeles based entertainment reporter with an affinity for CW superheroes. She graduated from Pepperdine University with a major in Media Studies and a borderline unhealthy obsession with TV in 2012. She would much rather spend the day binge-watching ‘The Flash’ or sorting ‘Game of Thrones’ characters into Hogwarts houses than venturing outdoors. TV words to live by: “Never ignore coincidence. Unless, of course, you’re busy. In which case, always ignore coincidence.”