Jason returns to Rosewood to warn Ali not to trust Mary. Meanwhile, the ladies make a discovery about Mary and Mrs. DiLaurentis that leads them to a storm cellar; Ezra gets a call about someone from his past; and Noel Kahn becomes a prime suspect.

One of the ladies goes rogue to find proof that Noel Kahn is Uber A, while the others search for evidence to back her theory. Meanwhile, Emily turns to Paige for comfort; and Jason and Aria team up to uncover the truth behind Mary's past.