Isaac Lahey is a student at Beacon Hills High School who is also on the lacrosse team.
He is played by Daniel Sharman.
When we first meet Isaac, he is working late at night at his job at the graveyard when something knocks over his backhoe dropping him into an empty grave.
He then witnesses something digging up a grave.
Derek Hale helps him climb out of the grave. During an interview with Sheriff Stilinski, it is hinted that Isaac's father abuses him, as evidenced by a black eye that he claims he got playing lacrosse. Isaac later meets with Derek in an abandoned train warehouse. (read more...)
Isaac accepts the bite willingly from Derek before his father is killed by an unknown creature. An exploration of his home showed his father locked him in a freezer chest and abused him often. He escaped police custody and is on the run. (read more...)
After the fight, Derek begins to train him and the others to survive. (read more...)
While discussing what to do about the Kanima, Isaac begins to question Derek's leadership choices. (read more...)
We learn Isaac had an older brother who would have been the same age as all the kanima's victims had he not died in combat. Isaac accompanies Derek to meet Scott at the Vet Clinic. Derek is snappish with him, telling him to stop bickering with Scott and not to touch the Vet's spice rack. Isaac is later given the task of injecting Jackson with Ketamine to subdue him. (read more...)
Isaac learns to control his shift during his second full moon. Derek chains him, Boyd and Erica in the subway car in the lair. Isaac breaks his bonds and escapes but comes back once he is in control. He tells Derek that he focused on his father to maintain control of his werewolf side. Derek believes this is because his father locked him in a freezer in the basement to punish him. Isaac reveals that his father's abuse was a recent development saying "he didn't used to." (read more...)
He goes to the Animal Clinic to ask Scott for advice after his pack mates' choose to leave Derek. While there, the Vet shows him how to use his pain transference on a sick dog. After first deciding to run away with the others, he changes his mind and returns to help Scott at the lacrosse game. (read more...)
After the game, he and Scott plan to track Stiles by scent. Derek and Peter show up and Isaac is swept along with them to Hale House. He then goes to the hospital and helps Scott move Jackson's cocooned body. He fights alongside Scott and Derek as they take on the Kanima. (read more...)
Isaac is revived by jumper cables, attached to a car battery and applied to his chest. His mysterious rescuer then attempts to get him to safety on a motorcycle. They are pursued by twin werewolves and crash. At the hospital, he is drugged into unconsciousness by another werewolf and then kidnapped by a third. (read more...)
Peter and Derek work to restore Isaac's lost memories. Under hypnosis at Dr. Deaton's office, he reveals that Erica is dead and The Alpha Pack is hold up in an abandoned bank. (read more...)