|“|| Lydia: "My mom's book club usually has more wine..."|
Stiles: "Well, they also probably didn't read books that cause violent hallucinations."
Scott: "That's why Malia's here."
Kira: "So none of us go running into traffic?"
Scott: "Or worse."
Sheriff Stilinski discovers eight large holes on the lacrosse field, suggesting that the Dread Doctors have created eight new Chimeras. Parrish begins teaching Lydia how to fight so that she can defend herself. Liam attempts to make things up to Hayden by paying her back for the $200 worth of drinks he spilled the several nights before. The group begins reading Valack's book, but Kira has difficulty reading it. Mason later explains to her that it is because Kitsune are confused by "language tricks.”
Theo records Kira's whispering in her sleep, and he later informs Scott that what she has been saying translates to "I am the Messenger of Death" in Japanese. Scott has an asthma attack at the high school. One of the new Chimeras, a boy named Josh, enters the school basement and chews through the power lines, absorbing the electricity before making his way to the hospital roof. Scott, Stiles and Lydia all experience traumatic visions because of their exposure to the book. Liam discovers that Hayden is a Chimera when she demonstrates superhuman senses. In the hospital, Scott and Malia are attacked by one of the Doctors, but they manage to escape. Meanwhile, Stiles goes to the roof of the hospital during a hallucination regarding his mother when she was sick and still alive. Josh, the new Chimera, attacks Stiles, but Theo rescues him and kills Josh in the process.
- Tyler Posey as Scott McCall
- Dylan O'Brien as Stiles Stilinski
- Holland Roden as Lydia Martin
- Shelley Hennig as Malia Tate
- Arden Cho as Kira Yukimura
- Dylan Sprayberry as Liam Dunbar
- Melissa Ponzio as Melissa McCall
- Linden Ashby as Sheriff Stilinski
- Ryan Kelley as Deputy Jordan Parrish
- Cody Christian as Theo Raeken
- Khylin Rhambo as Mason Hewitt
- Susan Walters as Natalie Martin
- Victoria Moroles as Hayden Romero
- Benita Robledo as Deputy Valerie Clarke
- Michelle Clunie as Mrs. Finch
- Cody Saintgnue as Brett Talbot
- Steele Gagnon as Young Scott McCall
- Henry Zaga as Josh Diaz
- Joey Honsa as Claudia Stilinski
- Marti Matulis as The Surgeon
- Douglas Tait as The Pathologist
- Caitlin Dechelle as The Geneticist
- Claire Bryétt Andrew as Sydney
- Marcy Goldman as Lorraine Martin
- Billy Snow as Phil
- Scott McCall, Lydia Martin, and Stiles Stilinski all experience suppressed memories in the form of flashbacks after reading The Dread Doctors novel. However, it remains unknown if these memories were suppressed by the Dread Doctors, or if they have any connection to them-- it is possible that these are just memories that they repressed themselves due to how traumatic they were.
- Lydia's memory was of when she was a child who came to Eichen House with her mother Natalie after they received a call that Lydia's grandmother, Lorraine Martin, had been injured. Natalie told Lydia to stay in the car, but she didn't listen and followed her in anyway. She then walked into the bathroom to find Natalie and a nurse with Lorraine, who had drilled a hole into her head behind her ear. Lorraine told her, "They're coming, Lydia. They're coming for all of us." This memory was triggered by Lydia seeing a bald patch behind Sydney's ear after she told her that she had alopecia.
- Scott's memory was of when she was a child, and he and his dog Roxie were attacked by a large German Shepherd. Roxie died, and the stress caused young Scott to have such a severe asthma attack that he was taken to the hospital in an ambulance. This flashback was triggered by Mrs. Finch reminding Scott that he wanted to be a veterinarian, and the intensity of the flashback caused him to have an asthma attack in real life for the first time since he was turned into a Werewolf.
- Stiles' memory was of when he was a child and visiting his mother Claudia at Beacon Hills Memorial Hospital. Claudia had gone up to the roof to get away from Stiles because her dementia made her believe that Stiles was trying to hurt and kill her. Sheriff Stilinski went to the roof to talk her down, but when young Stiles came up onto the roof, Claudia began attacking him. This memory didn't have an obvious trigger, but Stiles was so engaged in the memory that he made himself vulnerable to the Chimera Josh Diaz, who started attacking him just like Claudia was in the flashback.
- Kira was unable to read The Dread Doctors, and it was revealed that Kitsune have difficulty understanding language, which is why she was unable to focus on it.
- Beacon Hills Memorial Hospital
- Emergency Room
- Beacon Hills High School
- Lacrosse Field
- Mrs. Finch's Classroom
- Guidance Office
- Weight Room
- Locker Room
- Beacon County Sheriff's Department
- Sheriff's Office
- Parrish's Apartment
- Spare Room
- McCall House
- Living Room
- Scott's Bedroom
- Eichen House
- Womens' Bathroom
- "Attack" by Conway
- Parrish makes good on his promise to teach Lydia close-quarters combat by sparring with her at his apartment
- "Famous & Rich" by Naughty Queen, Sebastian Ingrosso, and Steve Angello
- Liam comes to Sinema to give Hayden more money to cover the shots he spilled several episodes ago. When the power goes out, he helps Hayden turn on the backup generator.
- "Bust One" by Proper Villains ft Metric Man
- Liam and Hayden practice lacrosse and soccer on the practice field at school
- "Freaks" by Timmy Trumpet ft Savage
- Liam and Hayden continue to challenge each other at their respective sports
- "It's Good" Ethel and the Chordtones ft Ryan Levine of Wildling
- Liam returns to Sinema to give Hayden more money to cover the shots, and she explains that she needs the money to pay for her medication so her sister doesn't have to pay for all of it.
- "Ghost Dance" by The Bright Light Social Hour
- Theo is working out in the weight room at the high school when Malia confronts him about him witnessing her flashback-hallucination in the previous episode