Guilty Party - Season 2 Episode 4

The students show up to class only to discover that they have been invited to a cocktail party at the Professor's house. Their invitations contain secrets- ones that they are not allowed to share with anyone else. Of course, the Party Twins and Alvaro alliance immediately breaks the rules. Once at the house, the Liars Club discovers that their task is to return that secret to its rightful owner, forever binding them together. When Bella and Benedict's cheating is revealed, however, more secrets spill forth.