Teen Wolf Season 4 plunges Scott McCall, a True Alpha werewolf and leader of his pack, and his human best friend Stiles Stilinski into a new wave of supernatural chaos. The season begins with Scott, Stiles, and their friends traveling to Mexico to find Derek Hale, a powerful werewolf who has gone missing. They soon discover that Kate Argent is alive and has captured Derek, who is mysteriously de-aged to a teenager. Kate, now a dangerous werejaguar, is struggling to control her new abilities.

Back in Beacon Hills, a new threat emerges: the "Deadpool," a hit list targeting supernatural creatures with bounties on their heads. Scott accidentally bites freshman Liam Dunbar to save him, turning Liam into his first Beta werewolf, who struggles with his new identity. The pack, including banshee Lydia Martin and werecoyote Malia Tate, works to uncover the identity of "The Benefactor" behind the Deadpool and the assassins carrying out the killings. After several close calls and investigations, Lydia discovers that Meredith Walker, another banshee, is the Benefactor, having enacted a plan overheard from a comatose Peter Hale, Derek's manipulative uncle.

The season culminates in a confrontation with Kate, who transforms Scott into a Berserker under her control. Liam helps Scott break free, while Derek undergoes a powerful evolution, transforming into a full black wolf. Peter Hale is defeated and imprisoned for his schemes, and Chris Argent makes a deal with the Calaveras to hunt Kate, who escapes.

Season 4 of Teen Wolf covers episodes 1-12. Here's everything that happened:

Season 4, Episode 1: The Dark Moon - Scott, Stiles, Lydia, Kira, and Malia travel to Mexico to find Derek, believing he's been captured by the Calaveras. They discover Kate Argent is alive and has Derek. Araya releases them to find Kate, and Braeden leads them to a church where they find a de-aged Derek.

Season 4, Episode 2: 117 - Kate, struggling with her werejaguar form, kills a gas station attendant. Derek, de-aged, trusts Kate and leads her to the Hale vault. Peter reveals Kate seeks a triskelion, but instead, someone steals $117 million in bearer bonds. Derek reverts to his adult form with golden eyes after fighting Berserkers.

Season 4, Episode 3: Muted - A new mute assassin murders a family, with only Sean Walcott escaping. At lacrosse tryouts, freshman Liam outplays Scott, threatening his captain status. Scott discovers Sean is a Wendigo and during a confrontation, Scott bites Liam to save him from a fall. Sean is killed by the Mute, leaving Scott horrified by his impulsive action.

Season 4, Episode 4: The Benefactor - Scott's pack deals with the newly bitten Liam, who struggles with the full moon transformation. Meanwhile, Derek and Sheriff Stilinski investigate the Mute, discovering he's an assassin hired by The Benefactor. At Lydia's lake house, a werewolf is killed by Violet, revealing her and Garrett's involvement with the Benefactor. The episode ends with Liam escaping and Argent returning to help Scott.

Season 4, Episode 5: I.E.D. - A new werewolf, Carrie, is killed by Garrett. Stiles investigates the Deadpool, connecting the assassins to the Hale vault theft. Liam's anger issues surface during a lacrosse scrimmage, leading to a confrontation with Derek. Lydia and Malia seek Meredith's help to decipher the Deadpool's keys. The episode concludes with Brett being attacked by Violet.

Season 4, Episode 6: Orphaned - Garrett kidnaps Liam, forcing Scott to help Violet escape. Derek and Malia find Satomi's pack slaughtered, discovering a wounded Braeden. Lydia and Stiles decipher the final Deadpool key, "Derek," just as Meredith commits suicide. Scott confronts Kate and finds Violet already dead. Peter offers to help Kate control her transformations.

Season 4, Episode 7: Weaponized - A mysterious outbreak sweeps Beacon Hills High, affecting werewolves and humans differently. Stiles investigates, encountering "The Chemist," while Scott's dad shoots the Chemist. The pack seeks refuge in the Hale vault, discovering a potential cure: reishi mushrooms. Malia finds the deadpool list, revealing her last name as "Hale", causing tension.

Season 4, Episode 8: Time of Death - Scott, with help from his friends, enacts a risky plan to draw out the Benefactor by faking his death. Scott "dies" on the operating table, while Stiles and Chris Argent attempt to contact the Benefactor. Derek's waning werewolf abilities are explored as Braeden teaches him to fight as a human. Lydia discovers her grandmother left behind a coded message, suggesting a connection to the Deadpool.

Season 4, Episode 9: Perishable - Deputy Haigh attempts to kill Parrish for the Dead Pool money, but Parrish survives, leading to Sheriff Stilinski getting shot. At the lacrosse bonfire, Scott, Liam, and Malia are targeted by another assassin. Lydia and Stiles uncover that Brunski from Eichen House was involved with Lorraine Martin's death. Ultimately, Meredith is revealed to be the Benefactor.

Season 4, Episode 10: Monstrous - Scott and Kira protect Satomi's pack from assassins hired via the Deadpool. Stiles and Malia uncover the Deadpool's origins at the lake house, finding an old computer. Lydia learns Meredith enacted Peter's plan, having overheard his thoughts while he was comatose. The episode concludes with all contracts terminated, but Peter reaffirms his intent to kill Scott.

Season 4, Episode 11: A Promise to the Dead - Deaton captures a Wendigo and visits Eichen House to learn about Kate's plans for Derek. Scott and Kira's date is interrupted when Kate attacks, later taking them to Mexico. Peter offers Malia information on her mother if she kills Kate. At the episode's end, Scott is transformed into a Berserker.

Season 4, Episode 12: Smoke and Mirrors - Scott and Stiles return to La Iglesia to save Kira from Kate, who reveals she can control Berserkers. Scott, now a Berserker himself, is subdued by Liam. Derek evolves into a black wolf, while Peter is ultimately defeated and imprisoned. The episode concludes with Chris Argent making a deal with the Calaveras.