Alison and the girls are invited to Noel's Halloween party, and each of the girls deals with different dilemmas leading up to the party.
Aria sees her father making out with a student, but decides not to tell her mother. Hanna's father recently left his family and her mother is distraught over their situation. Spencer desperately needs to win class president and succeeds with a little bit of help from Alison. Emily's boyfriend circulates a rumor that they had sex; even though the rumor is false, Emily lets people believe it to avoid facing the truth about her sexuality.
While picking out her Lady Gaga costume, Ali runs into the new girl, Jenna, and discovers that they have the same idea for their Halloween costumes. Although she warns Jenna off, the new girl shows up to the party dressed up in an even better Lady G outfit than Ali and proceeds to reject Ali's offer of friendship.
Ali also seems to have stalker who sends her mysterious texts and leaves a package containing a voodoo doll with the cryptic message, "It's my turn to torture you."
At the Halloween party, Ali plays a mean trick on the girls, making them think she's being attacked by a masked assailant. She's having a good laugh about it until her partner-in-crime, Noel, tells her he didn't actually participate because he was on a beer run. Ali gets another text from "A," but doesn't tell anyone about it.