On Teen Wolf Season 6 Episode 8, Theo tells the tale of Mr. Douglas, specifically how he's a Nazi and obsessed with the Ghost Riders. He was injured by one back in the 40s, but the Dread Doctors saved him. After coming out of their weird bath, Mr. Douglas gained the powers of a Ghost Rider.
Now, Mr. Douglas wants his own supernatural army, and he needs a hellhound's help. Mr. Douglas
enlists coerces Melissa and Argent to take him to the hellhound, and once he has Parrish, Mr. Douglas uses the Ghost Rider's whip on Melissa and Argent.
While Lydia, Malia, and Scott search for the supernatural rift, Liam, Hayden, and Mason stay behind in the precinct. The Ghost Riders can't leave Beacon Hills if there are still people in Beacon Hills. The Ghost Riders show up at the precinct and take Mason and Hayden.
Lydia, Malia, and Scott find the supernatural rift, and Mr. Douglas finds them. Mr. Douglas first tries the "we all want the same thing" angle, but then Liam shows up and spills the Nazi secrets. Oh well, Mr. Douglas didn't need them anyway. Parrish helps Mr. Douglas get through the rift, and it closes before Scott and company can go through it as well.
To make matters worse, some Ghost Riders show up, and they aren't too happy to find trespassers. Liam and Lydia manage to escape because a Ghost Rider seems to fear Lydia, and he lets them go. Peter saves Malia and Scott's asses, but it comes with a cost. The Ghost Riders take Peter (again). Well, at least Peter knows where his seat is at the train station.
Meanwhile Noah remembers Stiles, and he also remembers that Claudia died. Afterwards, Noah says that he saw Stiles, briefly. Scott thinks Noah opened up a rift, and if he can do it once, well then maybe the pack can open one again.