Emma wakes from a nightmare in her kitchen holding a knife. 

Gustavo and Brooke wake up together. Brooke goes to shower and he sniffs her lipstick. 

Audrey tries to explain to Emma, but she's angry and doesn't believe her. Emma finds a tape hanging in her locker. 

Audrey asks why Noah recorded their conversation. He says he recorded it by accident and didn't send it to Emma. Audrey figures it must have been Zoe. 

Emma listens to the tape of Ms. Lang talking about her violent tendencies. 

Zoe admits to sending the file to herself, but swears she didn't send it to anyone else. 

Miguel tells Maggie that Gustavo shot his friend in the face in Phoenix. Miguel questions whether it was really an accident.

Emma goes to visit Ms. Lang and she screams in her face. 

Gustavo snoops around in his dad's office and finds his files on the killings. 

Noah and Zoe finally have sex. 

Kieran and Emma break into Ms. Lang's house and discover that she knew Piper. 

Noah realizes the killer has been bugging him. 

Ms. Lang and Piper both grew up at a group foster home. Emma, Kieran, Noah, and Zoe plan to meet there. 

Gustavo tells Brooke Jake was working with her father. 

The group finds a party going on at the group home. Emma discovers that she and Audrey are "throwing" the party. Audrey is lured there by the killer. 

Emma and Audrey find Piper's decomposing body.