'The Jenna Thing' [Original air date: June 15, 2010]
The circumstances surrounding Alison's disappearance continue to haunt Aria, Emily, Spencer and Hanna, as questions arise about the night she went missing. To complicate matters, Jenna's return to Rosewood makes the girls face an unpleasant past and an incident that sealed their friendship forever. Can the girls face what has taken place in their past, especially since "A" won't let them forget? Meanwhile temptation is everywhere they look, as Aria tries her hardest to stay away from Ezra and Spencer won't shy away from her sister's fiancé, Wren.