On Teen Wolf Season 6 Episode 3, Hayden discovers that her classmate Gwen lost her sister, Phoebe, to the Ghost Riders. Gwen has been going all around school asking people about Phoebe. No one remembers her, and every trace of her has been erased. It's up to Liam and company to keep Gwen safe because Gwen has seen the Ghost Riders.
What do they do? They throw a party at Scott's house, of course! They line the house with mountain ash, in the hopes of keeping out all supernatural creatures. Shockingly, it doesn't work. The Ghost Riders crash the party anyway.
Liam and company manage to hold the Ghost Riders off, with some help from Parrish. After a stare down between Parrish and a Ghost Rider, the Ghost Rider just leaves in a flurry of leaves, as one does.
Meanwhile, Malia, Lydia, and Scott try to figure out what a Stiles is. The Sheriff tells them that Stiles is a family nickname his dad, Elias, used when he was in the army. Even though the Sheriff forbids them from going to see his dad in the nursing home, Scott, Lydia, and Malia go anyway.
Elias has dementia, and yet, he remembers the real timeline. He tells the Sheriff to go home to his "dead wife and loser son." Ouch. This does prompt the Sheriff to examine the dream he had recently where he and Claudia are discussing baby names. Stiles is named after Claudia's dad.
Chris Argent is back in town! He announces his presence by breaking into Melissa's kitchen. He needs to get a look at a body in the morgue, specifically the body that was discovered at the school. The body that has teeth marks on the back of his skull.
This isn't the first body like this that Argent has found. He believes a werewolf with a particularly strong jaw made those marks. The wolf is stealing the pineal glands from its victims.