Teen Wolf Season 4 Episode 2 117
Previously: They rescued Young Derek from the ruins.
Flashback to when Derek is in the showers trying to turn back to human. He was using his wolf powers during the game to gain an advantage. His uncle comes and tells him to use an amulet to calm himself.
Present day, Kate is fighting with her monster side in a gas station bathroom trying not to turn. She turns around when the station attendant opens the door and she is not a wolf.
Elsewhere the gang arrive home with young Derek and take him to the vet. Stiles makes comments, the doctor sends the kids home. Lydia stays with him.
Derek wakes up and doesn't know who Lydia or the doctor is. He attacks them and runs away to where his house used to be. He finds it completely burned down. The police arrest him for trespassing and run his prints. They keep getting Derek's record.
Scott and Stiles go to the station and lie to him to get him free. Scott goes to Peter to talk about Kate while Stiles take Derek to Scott's house.
Kate turned Derek to an age when he still trusted her so that he will show her to the Hale family vault underneath the high school. The ganng arrive just in time to get ambushed by creatures. Peter finds Kate and Derek in the vault and tells Kate the amulet is actually just an object to focus on. As they are about to fight, someone throws down some smoke bombs and sneaks in to steal something from the locked vault in the corner.
Derek hears Scott's cry for help and goes to save him. After the battle, he turns back to normal and has golden eyes. Peter freaks out about the thing they took, it was "bonds, bearer bonds."