Visiting Mona is driving a wedge between Hanna and Caleb and Hanna is forced to weigh up how honest to be with him.

Testimony at Alison's trial reveals a plethora of lies; Spencer, Aria, Emily, and Caleb follow a string of clues in hope of uncovering information that will clear Hanna.

After Alison is confronted with a sudden, mysterious jeopardy, the Liars decide to take things into their own hands for a counterattack. Hanna and Caleb work together to develop a plan to come face-to-face with the tormentor. Emily and Spencer team up to investigate if Mona had any involvement with the murder. Aria and Ezra continue to work on the book though it might be more difficult than anticipated.

Meanwhile, Ali encounters an unexpected visitor.

Ali’s turn at the game forces her to face a monumental personal decision, made even more difficult when A.D. triggers Ali to remember a forgotten trauma. Spencer has a long overdue conversation with her father about his past sins and recent whereabouts. Emily continues to navigate working at Rosewood High with both Ali and Paige, especially when Ali comes to a troubling realization about her pregnancy, and Paige makes a big decision. Aria continues to question the fate of her relationship with Ezra and bristles under A.D.’s taunts. And, in the search for Mary Drake, Hanna and Spencer run into a familiar face with a shocking secret.