The “Teen Wolf” pack is going to have some trouble killing the Beast of Gévaudan in the final episodes of Season 5B. Though Lydia (Holland Roden) learned exactly how the creature was first killed in the 18th century, she decided that she couldn’t work alone. However, killing the Beast might not be on the agenda now that his identity has been revealed. Mason (Khylin Rhambo) is the one they’ve been after, but in episode 19, Scott (Tyler Posey) and the pack will have to fight the Dread Doctors to get him back.

“With the identity of the Beast finally revealed, Scott and his friends are in a race against time to stop the Dread Doctors from implementing their final plan,” the synopsis for the MTV drama teases. The Doctors have been trying to get Mason to remember the Beast’s first life as Sebastien Valet. If he recalls those memories, Mason himself will disappear.

Rhambo is super excited about playing the Beast. “Since I was first cast on the show, I wanted to be involved in some type of supernatural element. That was my dream,” Rhambo told TVLine. “To be such a huge, ravenous creature — that was really cool. I didn’t even guess myself. I truly didn’t.” However, the characters on the show are less enthusiastic and much more terrified.

The pack can’t keep Mason from the Dread Doctors because he escaped in episode 18. Corey (Michael Johnston) used his powers to make Mason invisible and helped him get away from Scott and Liam (Dylan Sprayberry). That plan will go south quickly. In the trailer for episode 19, titled “The Beast of Beacon Hills,” Corey tells Scott that the Dread Doctors took Mason.

Meanwhile, the trailer also shows Braeden (Meagan Tandy) in a house with the Desert Wolf (Marisol Nichols). It looks like the two will face off. Since this is the penultimate episode of the season, the stakes are even higher than usual. This could be the final showdown for Malia’s (Shelley Hennig) mother.

“Teen Wolf” Season 5B, episode 19 airs Tuesday at 9 p.m. EST on MTV.