Teen Wolf Season 5 Episode 1 opens on Eichen House and Lydia showering in a seemingly catatonic state. The nurse believes she's faking and instructs the other nurse to increase her medication dosage. 

He begins to stick Lydia painfully over and over with the needle, eventually drawing blood. It's apparent the nurse enjoys inflicting pain on her. Just as he's about to stick the needle in Lydia's neck, she sits up and screams.

Lydia attempts to escape and fights the orderlies. Her banshee scream creates a force field that knocks her opponents down. Aiden appears just as Lydia is about to escape. He tells Lydia her treatment isn't done and tases her. Lydia screams all her friends are going to die.

Scott and Stiles discuss where to live during college. Scott is worried life is about to get really good or really bad, to balance the cosmic scale.

Liam is chained to a tree to ensure he's in control. Last full moon he lost control and terrorized the town. Scott asks Liam if he's in control. He says yes, but his palms are bloody from digging his nails into his hands.

Parrish is angry Sheriff Stalinski is keeping him on desk duty. He sends Parrish out on a noise complaint.  

Parrish investigates the noise in an old home. Someone is behind the wall. A werewolf explodes through the wall. The werewolf asks where Scott McCall is, but Parrish refuses to answer. The werewolf attacks him.

Stiles picks up Malia. She's waiting to see if she passed summer school and is officially a senior.

Scott's mother is rushing to work and the werewolf that attacked Parrish is waiting in the house. The werewolf finds Scott's note saying he's at the high school for Senior Scribe.

Kira is stuck in traffic with her parents. She's going to be late to Senior Scribe.

Scott, Stiles and Malia are at the hospital. Scott mentions he hasn't spoken to Kira since she returned from New York. Stiles is concerned Scott may have given Kira the wrong impression by leaving things too casual between them. Stiles' concern makes Scott concerned.

Scott returns to his house and the refrigerator is demagnetized, the clock goes haywire and the house starts shaking.

Post werewolf attack, Parrish calls for help. He hallucinates Lydia and they almost kiss. The Sheriff finds him and brings him to the hospital. Parrish wakes up, eyes glowing and healed.

Scott finds Kira in traffic. Kira reassures Scott she didn't have any fun in New York, meaning she didn't sleep with anyone else while she was gone. They kiss in the rain.

Parrish thinks the werewolf can steal Scott's "true alpha" power. The werewolf finds Scott and Kira at school, waiting for Senior Scribe, and attacks.

Stiles tells Malia he is worried he'll lose touch with his friends after he graduates. Liam finds Stiles and Malia and tells them Scott is in trouble.  

Scott and Kira fight the werewolf. He stabs Scott with his claws. It appears he's stealing Scott's power and killing him, but Scott stops him. He tells the werewolf he has two choices. Stay and Scott will break something else or run. Stiles advises the werewolf to run and he does.

During the fight another werewolf shows up to help. It is Scott's fourth grade friend Theo. He's returned to Beacon Hills because he wants to be part of Scott's pack. 

Malia passed summer school. The entire pack goes to Senior Scribe where they write their initials on the library shelf. Scott includes Allison's initials next to his.

The werewolf Scott defeated begs for more power from three robotic monsters. They tell him no second chances and kill him. Three black crows fly out of his body.

Back to Lydia in Eichen House. The episode is a flashback. It's not Aiden she sees, but her doctor. He asks what happened to her friends.

Lydia says she doesn't remember, but there are several flashbacks: Scott and Liam fighting; Mrs. McCall slapping the Sheriff; Kira gets into a car and looks back at Scott as light explodes behind him; Parrish on fire and eyes glowing; Malia cowering from the Desert Wolf; Styles unconscious in a car wreck.  

Lydia repeats she doesn't remember and the doctor starts drilling into her skull.