The killer broke into an evidence room one year ago and stole the Brandon James mask.
The sheriff questions Seth Branson about the knife found in his classroom.
Emma tells her mom that she wants to talk to Branson. He denies knowing anything about the murders and says he can't talk about his past.
Brooke notices the webcam turn on in her room at Jake's house.
Emma, Noah, and Audrey discuss whether Branson could be Emma's half brother.
Piper tells Emma she found Brandon's mother. Emma goes with her to talk to her about Brandon. She tells her that Brandon's son came to visit. She can't remember his name, but when Emma asks if it's Seth, she says yes.
Kieran asks Emma to the Halloween dance.
Audrey tells Noah that Rachel filmed everything and they wonder if she could have filmed Branson doing something.
The sheriff follows up a lead on Branson's cell phone records and tries to find a witness who can ID him. He checks out a house and is attacked by the killer.
Brooke calls Emma to invite her to a party at her house instead of the dance. Emma says she's meeting Kieran there, but they can come after.
Audrey and Noah find a video of Nina with Kieran. Audrey shows the video to Emma at the dance.
Emma confronts Kieran about the video. He explains he met her at a bar and he drove her home, but nothing else happened.
Piper tells Emma that she took the yearbook to Brandon's mom and she pointed out Kieran as the one who came to visit her.
The lights go out at the dance and a video of an injured Sheriff Hudson appears on screen. An APB goes out on Branson who has escaped from jail.