Hanna worries that her mother is keeping a dangerous secret and is determined to protect her at all costs, which leads her to an uncomfortable meeting with Detective Holbrook. A clue in Ali's things leads the Liars to a creepy mask maker, who takes a shine to Emily and may have ties to another Rosewood resident. Spencer and Toby continue their search into a painful chapter of Toby's past and Melissa returns to Rosewood. Meanwhile, A targets Emily's mom, leading Aria to make a desperate plea of Ella.