As the girls are forced to stay in Rosewood, questions about the new mystery surface. A restless Aria starts to look suspicious as she heads back to Boston a little too quickly. But could Aria really be the one behind this? As Spencer, Emily and Hanna find themselves back in familiar territory, they aren't happy with going about solving this puzzle "the old way."

Meanwhile, Emily continues to lie about her life in California and Alison keeps a close eye on her friends.

Aria, Emily, Hanna and Spencer find themselves back in familiar territory with the Rosewood P.D. knocking at their doors looking for answers and their actions now affecting the loved ones around them. With her mother's job on the line, Hanna tries to come up with an alibi that could save all four of them with the help of her old high school friend, Lucas.

Meanwhile, Emily comes clean about the last five years, and Aria goes the extra mile to keep Ezra's second book in play with her boss.

While new discoveries are made in the investigation of Charlotte's murder, the truth begins to emerge about the Liars' personal lives. Spencer is concerned to learn her mother is keeping a secret of her own. Aria confesses to Liam how deeply she's involved with Ezra's book. Ali admits that she and Elliott are more than just friends. Mona reveals where her true allegiances lie. Caleb, Spencer and Hanna deal with the complications of new relationships.

Meanwhile, Emily and Hanna each receive shocking threats that elevate the seriousness of the situation.

As romantic relationships move forward, the Liars investigate a new suspect in the murder case. With Ezra back in Rosewood, Aria must tell him the truth about her involvement with his book. Spencer and Caleb deal with a media leak that affects the campaign. Hanna takes a look at her life after an incident at work. Emily gets harassed by the stalker while she continues the search for Sara.

Meanwhile, two lovers finally tie the knot with the help of a special officiant.

After the stalker nearly killed Emily, the Liars begin to take the threats more seriously and attempt to keep their mouths shut to prevent any further harm. Caleb must deal with the collateral damage of taking the blame for the leak about Yvonne; Spencer tries to comfort him and get him to tell the truth. Emily goes on a mission to track down who came after her. Aria and Ezra move forward with the novel.

Meanwhile, Hanna avoids dealing with her personal life.