|“|| Kira: This is beyond depressing. He was just trying to help her. Why would she go after him?"|
Lydia: "I guess she wasn't in control of herself."
Kira: "But it wasn't even a full moon."
Lydia: "Maybe a Werewolf with night terrors is worse than a... You know, there are cases of people who accidentally murdered their entire family while in a night terror. They had no idea what they were doing. It's called "homicidal somnambulism."
Kira: "So, if Tracy's killing people she doesn't really want to kill, she might not actually be awake."
Lydia: "She's still in a night terror."
Tracy goes on a killing spree, brutally murdering her father and her psychiatrist. Liam, Mason and Brett discover that Tracy was buried alive in the woods and dug her way out. Lydia and Kira figure out that Tracy is still trapped in a night terror and thinks that she's still asleep. The next morning, the McCall Pack meet in the school bus bay to discuss how they will deal with both helping Tracy and preventing her from harming anyone else; this group includes Mason Hewitt, who was informed of the existence of the supernatural world the night before by Liam and who is awestruck by the sight of the pack in action.
After Tracy appears at the high school and hurts Hayden Romero (who is shocked by disbelief when the claw wounds on her wrist heal in seconds) before falling unconscious, Scott, Stiles and Malia bring Tracy to Deaton at the veterinary clinic, where Tracy grows a tail and is revealed to be a Kanima. She paralyzes Scott, Stiles, Deaton and Malia and escapes, breaking through a barrier of mountain ash with ease. Tracy then goes after Lydia's mother at the Sheriff's station; during the resulting fight, Kira inadvertently unleashes her Kitsune powers and manages to cut off Tracy's tail, but not before Tracy uses it to badly wound Lydia. Malia arrives and manages to subdue Tracy, but the Doctors immediately appear and kill Tracy in front of her.
Meanwhile, Liam and Mason seek out Brett Talbot to see if his Alpha, Satomi Ito, happened to have bitten and turned Tracy, but Brett insists that their pack is no longer recruiting after the events of the Deadpool. The three then set off for the nature preserve in hopes of finding a necklace belonging to Tracy that he found in the hole he had fallen into several nights prior. However, though they do not find the necklace, they do find a second hole and realize that the new shapeshifters have been buried alive and forced to dig themselves out.
- 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
- Linden Ashby as Sheriff Stilinski
- Seth Gilliam as Alan Deaton
- Ryan Kelley as Deputy Jordan Parrish
- Cody Christian as Theo Raeken
- Khylin Rhambo as Mason Hewitt
- Susan Walters as Natalie Martin
- Ashton Moio as Donovan Donati
- Kelsey Asbille as Tracy Stewart
- Victoria Moroles as Hayden Romero
- Tom T. Choi as Ken Yukimura
- Michelle Clunie as Mrs. Finch
- Salvator Xuereb as Mr. Stewart
- Benita Robledo as Deputy Valerie Clarke
- Cody Saintgnue as Brett Talbot
- Marti Matulis as The Surgeon
- Douglas Tait as The Pathologist
- Caitlin Dechelle as The Geneticist
- The episode's title refers to the night terrors experienced by Tracy Stewart and the dreamcatcher Kira and Lydia found in her bedroom, which was given to her by her father to help with her night terrors.
- Sheriff Stilinski and Natalie Martin try to go on a date on two occasions in this episode, but are unable to do so because of Tracy's attack.
- Mr. Stewart - mauled to death; killed by Tracy Stewart
- Psychiatrist - mauled to death; killed by Tracy Stewart
- Tracy Stewart - overdose of Modified Mercury; killed by the Dread Doctors
- Beacon County Sheriff's Station
- Sheriff's Office
- Holding Cells
- Downtown Beacon Hills
- Warehouse District
- Beacon Hills High School
- Bus Bay
- Mrs. Finch's Classroom
- Mr. Yukimura's Classroom
- Girls Restroom
- Lacrosse Field
- Beacon Hills Animal Clinic
- Exam Room
- Stewart House
- Tracy's Bedroom
- Beacon Hills Preserve
- "Set It Off" by Life In Film
- Lydia and Kira are giving Malia a driving lesson in her new Toyota Camry.
- "Ilium" by Alex Metric & Mark Yardley
- Mason and Liam watch as Brett practices lacrosse on the Beacon Hills High School lacrosse field.
- "Take It All" by Ruelle
- Malia recovers from her Kanima-venom-induced paralysis and leaves the animal clinic to go find Tracy. Scott pleads with her to save Tracy and not kill her.