'Teen Wolf' Recap: 'The Beast of Beacon Hills' Season 5 Episode 19, Dread Doctor Dilemma

Last week MTV's Teen Wolf fans were greeted by a familiar face.

In "The Beast of Beacon Hills," episode 19 of season five, the pack has to deal with the new information on the identity of the beast as another Dread Doctor could be in the making.

Now that Scott, Lydia, Stiles, Malia, Kira, Hayden and Liam knows the identity of the Beast of Gevaudan, they have to prevent Mason from finding out that Sebastien was the original beast. He can't learn his true identity or else the beast will take over. In order for them to prevent that from happening, they need to stop the Dread Doctors before they complete their final plan which could prove to be catastrophic.

Theo tries to coax Josh into putting on the fourth Dread Doctor mask with help from Deucalion who reveals that the surgeon was the original creator of the mask.

He also reveals that the masks has electro-magnetic fields within them and Josh is the only one in Theo's pack who can absorb electricity. Meanwhile, Kira realizes that she has to be a part of the team to help Mason.

The action kicks off as Mason and his kidnapper wakes up in the tunnels. Mason says he can't be the beast because he is not a genetic chimera. Corey asks Mason where he was all of the times he sent out the transmissions.

Mason says that he can still be found by frequency. When Corey asks if he is talking about Scott, Mason says no, them, as the Dread Doctors make their way towards him.

Corey and Mason begin running through the tunnels but everywhere they go another Dread Doctor follows.

They are chased to an opening but the Dread Doctors begin calling Mason's name and he hesitates for a second. Corey grabs him and they finally make their way out of the tunnels. However, as they run away Mason can hear the Dread Doctors calling.

It's raining heavily and the Dread Doctors have surrounded them. Corey tries to camouflage Mason but a Dread Doctor swipes and Corey falls to the ground. He turns to watch them walk away with Mason.

Tracey and Theo are trying to get Josh to put the Dread Doctor mask on because he is the only one who could survive it. Deucalion says that the properties of the mask are electromagnetic and it was a product of genius and madness.

It was created by the surgeon who harnessed electromagnetic fields in the mask giving them a unique and deadly power.

Josh attempts to put the mask on but he doesn't. He tells Theo if he wants to know who it is, he should do it himself.

Lydia is speeding off to stop Parrish from leaving. She talks to the Sheriff who says he has a lead on where he is. Parrish is heading off but he is stopped by tire spikes set up by the Sheriff.

Lydia arrives and Parrish tells them that they are crazy. He says he can't stay because he is the reason the people he sees die.

Lydia says that there is a reason he was drawn to Beacon Hills and the Sheriff hands him his deputy badge.

Scott wakes up in a panic telling Kira that they have to find Mason. He isn't in good shape and Kira tells him that they will find Mason but he isn't going anywhere until he heals. Stiles closes the door after overhearing them and sharing a look with Kira.

Then, Stiles is approached in the hallway by Malia and Braeden. Malia tells him that her mother might be trying to kill him as well.

Stiles says he should have a gun and Braeden refuses. When he does get the gun hilarity occurs and he realizes that it wasn't the best idea.

Liam is racing through the woods trying to track Mason. He falls and loses the scent. Hayden is there with him and says she will help him find it.

Scott wakes up the next day and sees his pack at the table trying to figure out all of the places that Mason could be. Scott tells them they should just ask Corey and pulls him out of camouflage.

Corey tells them that the Dread Doctors took him and he couldn't help. Meanwhile, the Dread Doctors have brought Mason to their lab and they are painfully extracting blood from him.

Tracey presents Theo with the tails but he says they don't know who they belong to. Deucalion mocks Theo and asks him where his pack is since Corey and Hayden are both missing. Josh thinks about leaving and Deucalion says the pack is dwindling.

Theo tells Tracey to numb his tongue but Deucalion stands up and reveals that he was prisoner to gain the trust of Theo.

He says he wants the eyes of Scott and pulls out the IV he was hooked up to.

Kira is trying to figure out a way to control the Kitsune and her father tells her that they need to enlist some help. She picks up the pieces of her sword as they set out to find more help. Meanwhile, Deucalion is showing Theo what his power is. Deucalion tells Theo he needs to take the power her needs.

Theo says he understands and attacks Josh. He absorbs all of the electromagnetic power from him.

Theo turns to Tracey and asks her what she thinks. She says that Josh was inexperienced and if Theo has the power now, he can put on the mask.

Lydia leads Parrish to the Nemeton and she tells him that he can still save them all. He has a rush of images of all of the bodies he buried within it as he touches. Then, the Nemeton begins to glow.

Deucalion is urging Theo to put on the Dread Doctor mask and take his place as a real alpha.

He puts it on and begins screaming in pain like all of the others who have tried it on in the past. Tracey has a worried look but Deucalion seems calm.

The team is at school as if everything is normal and Liam asks Scott if what they are doing is stupid. Scott says they are desperate and opens the door to find Tracey and Theo. Theo appears to be fine and Scott asks him if he put the mask on. Theo said he did not see Mason and that he is willing to compromise.

Theo wants the map in exchange for information. They leave the room and Liam asks how desperate they are. Scott tells him they are incredibly desperate.

Tracey and Theo return and Deucalion tells them to carry out a plan that involves Tracey paralyzing the Beast. The Sheriff, Stiles and Lydia go over all of the heights everyone is going to to find Mason.

Lydia says she hopes they find Mason and not the Beast.

Theo and Scott are going to follow the map to find the currents they are looking for.

Someone resembling Mason is being rushed into the emergency room, Lydia is on the phone with Malia who says she should be keeping Stiles safe and her mother overhears the conversation.

Malia is held up in the house with Braeden and she seems very nervous about Stiles being out without any protection. Stiles, Lydia and the Sheriff are patiently waiting for any word. It happens to be getting closer to the full moon as Theo and Scott make their way to the currents. Scott tells Theo that he shouldn't trust Deucalion.

Once they reach a certain point, Theo asks what direction they need to go. Theo realizes that he won't get the answer until he gives up what he saw with the mask.

He says he saw a man dying in the snow with a spear in him. They recognize the vision from Gerard's story and Liam ends up leading them to Mason.

They find him in the Dread Doctors lair and he is connected to an unknown device. This does not look good at all. Kira calls Scott to tell him that she is going to leave but she ensures him that she will be back because Scott was right when he said that they need to be the ones to save Mason. She hops into her car after leaving the message and drives off. Scott and Liam are trying to get the device off of Mason as Theo watches on.

Mason tells them that it's in his brain. Scott asks Theo what Mason is connected to but he says he doesn't know. Scott tells Mason not to worry and they will get him out.

They try to removed the device but Mason screams in pain. Before they can go any further Scott turns Liam's attention to a Dread Doctor and Theo slowly finds out they aren't alone as well.

Stiles and Lydia are still waiting for a sign and Scott's mother reveals that Mason had a twin but ate him while they were still in his mothers stomach. A Dread Doctor approaches Theo and says that he is a failure. Theo says they are taking him and Scott tells Liam to get Mason out of there.

The Dread Doctor says Theo isn't a complete failure.

Scott tries to convince Theo to avoid giving the Doctor what he wants and Theo tells the Dread Doctor he is taking Mason and he is taking what's his. He turns into a werewolf and prepares to attack.

Malia can't reach Stiles and tells Braeden something is wrong they have to go. Malia knows something is wrong. Braeden jumps up on alert with a gun in her hands she sees the ash line is broken and Tracey walks by.

In the house Corinne is hiding.

Chris and Gerard are trying to figure out if they should help Mason but Gerard just wants the pike.

They say they need a lot of firepower and Parrish comes in asking them how much they need with his eyes growing.

The Dread Doctors tell Theo that true evil only comes from corrupting something truly good. Liam realizes that they were referring to Mason. Theo begins an all out assault on the Dread Doctors. Liam and Scott are forced to help but Mason is feeling the effects of his treatment.

He rips the connector from his body all on his own. The Dread Doctors say transformation without frequency and Mason rises.

Scott calls out for Mason but as he turns into the beast, Mason says that it's not his name. Now they are all staring at the Beast of Gevaudan.

Corinne wanders the halls using extra caution and Braeden is also being super cautious. Corinne steps on nutshells giving away her location. She and Braeden are caught up in a fight as Malia watches on. Braeden gets the best of Corinne and knocks her down.

Then, Braeden takes off running. Corinne wakes up and asks if Braeden is still there. Braden is outside the door and the ash line has been redrawn. It's just Corinne and Malia in the house now.

Elsewhere, Kira is calling out to the Skin Walkers asking them to tell her how to save her friends. They say they can help her but it comes with a price because everything has its price. Liam and Scott watch on as the Beast rips the Dread Doctors apart. He throws Theo to the side and as the Beast approaches the last Dread Doctor, the Dread Doctor says success.

They follow the Beast outside where it is attacked by Parrish and Chris. When the beast returns to its manly form, it's Sebastien Valet.

Gerard asks Sebastien if he remembers his name and he says the name Argent before disappearing. Mason is no more.

"The Beast of Beacon Hills" really did have the sparks flying in Teen Wolf.

With one episode left, Scott and his pack finally rid themselves of the Dread Doctors but the danger of the beast still exists.

Fans will have to tune in next week to find out what happens on Tuesday at 9PM EST.