with no swimming ability, to nearly drown years ago at a swim team pool party held by Isaac's swim coach father. Because of the connection between the Kanima and his master, Jackson discovers he now fears water. Held hostage by Matt at a local police station, Scott, Stiles, their parents, and Derek are able to escape, although Scott transforms for the first time in front of his mother, Melissa McCall (Melissa Ponzio), leaving her horrified. Gerard drowns Matt and becomes the Kanima/Jackson's new master. Derek learns from Peter that the Kanima's weakness is the love interest of its human form, in this case Lydia. Jackson is hospitalized whilst developing a new stage of the Kanima, whereby he ends up in the hands of his former friends. Boyd and Erica try to flee from Derek for their own safety, but are captured and tortured by hunters. Realizing his father, Gerard, corrupted his daughter Allison, Chris Argent (JR Bourne) helps Scott and his allies stop the Kanima from evolving. Gerard tries to confront the group by forcing Derek to bite him and cure his cancer, but Scott reveals he switched his medication with mountain ash. Gerard's body rejects the bite and he quickly disappears. Before the Kanima/Jackson can kill Allison, Lydia reaches out to him and saves him with her love. He evolves in to a new werewolf, as the Kanima is now dead. Feeling guilty over her grandfather and his influence over her, Allison breaks up with Scott but she promises to come back. While Erica and Boyd are leaving Beacon Hills, they encounter a pack of menacing Alphas. Peter and Derek reveal to Isaac that Derek was building a pack to combat the impending Alpha Pack and Peter knows that they have arrived. Also appearing during the season are Dr. Deaton (Seth Gilliam), Adrian Harris (Adam Fristoe), Coach Bobby Finstock (Orny Adams), Sheriff Stilinski (Linden Ashby), Danny Mahealani (Keahu Kahuanui), Marin Morrell (Bianca Lawson) and Mr. Lahey (John Wesley Shipp). Kali, Ennis, Ethan and Aiden make a brief appearance in the season finale, "Master Plan", as the members of the Alpha Pack that kidnapped Boyd and Erica. As of Season 3, they become recurring characters, with their leader Deucalion introduced in "Tattoo", the first episode. These characters are played by Gideon Emery (Deucalion), Brian Patrick Wade (Ennis), Felisha Terrell (Kali), Charlie Carver (Ethan) and Max Carver (Aiden). Cast Main Tyler