Who killed Toby's mother? Who hit Alison in the head with the rock the night she went missing? Who is Red Coat? Who killed Bethany? Who is the Black Widow? Why has "A" been targeting the PLLs all this time? After years of torture, Alison, Aria, Emily, Hanna and Spencer finally come face-to-face with their tormentor and learn the story of how and why Charles became "A."

All is revealed as the ultimate endgame comes to light.

This special black-and-white episode gives a nod to 1940s-era film noir as Spencer's numerous sleepless nights with the help of prescription pills start to take a toll on her.

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.

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.

With the fallout of Hanna’s abduction still weighing heavily on the PLLs, the Liars begin to grow suspicious of Elliott Rollins as Ali’s condition worsens. Tensions rise between Liam, Aria and Ezra as they work on the book together. Spencer and Caleb are on edge, as neither of them want to talk about the awkward elephant in the room. Meanwhile, Emily receives a disturbing phone call and tries to find a way to see Ali.

Emily butts heads with teenager Addison, who appears to be a new version of high school Ali, and who may be connected to a familiar foe. Spencer confronts her mother about keeping family secrets. Aria confides in Holden about her relationship with Ezra, while Spencer turns to Detective Furey for help. And Jenna stirs up even more trouble when she returns to Rosewood with some insight into Noel Kahn and recent events.

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.

With the Rosewood P.D. breathing down Hanna's neck about The Radley security footage, she opts to confess the truth to those closest to her in hopes they can help. Aria continues to search for answers, with help from Emily, on whether Ezra is as guilty as he seems. Spencer works together with Caleb to track down the new threat. Meanwhile, there is awkwardness all around when new love interests emerge and old ones resurface.

Hanna refuses to let "A" frame her for Mona's murder; Spencer's actions put Toby in a bind.

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.

In order to prove Sara Harvey is behind the threats, Team Sparia reunites to find evidence of Sara's involvement before they go to the cops. Caleb puts together a plan with Hanna to fight back against the new stalker by using the security footage tapes. Meanwhile, Aria gets unexpected news from her family, and Ali comforts Emily in her time of need.

Emily goes up for a position as the Rosewood High swim coach, only to learn that her ex-girlfriend Paige is also up for the job. Hanna is visited by Mrs. Grunwald after she has a vision that the PLLs are in danger. The girls track down the doctor who delivered Mary’s baby in order to get answers. Ali decides to go back to work to help bring some normalcy to her life again.

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.

Jenna returns to Rosewood and befriends another one of the Liars’ enemies, making her the PLL’s number one suspect for Uber A. In order to leave the psychiatric hospital, Ali must be released into the care of a relative, leaving her under the suspicious watch of Mary Drake. Spencer enlists Hanna’s help to search for Caleb as he’s missing in action. Aria and Emily stumble upon a secret apartment they hope will lead them to more answers.

Hanna is sure Jenna is to blame for a recent professional setback and is forced to bring Caleb up to speed on current events. Aria and Emily team up to investigate Sydney for more information about Jenna and her connection to A.D. Spencer grows closer to Detective Furey, while Aria struggles with her current situation with Ezra. Hanna’s turn at the game is more intense than she bargained for and leads to shocking consequences.

Alison attempts to regain her position as leader of the gang upon her return to Rosewood High.

Spencer and Toby are at odds while Emily and Aria struggle with situations that are out of their control.

With all signs pointing to Lesli as the tormentor in the hoodie, the PLLs are on a mission to get concrete proof before bringing their findings to the police. But as the girls ramp up their investigation, "A’s" threats escalate. Meanwhile, a friend of Emily’s makes her a surprising offer, and Spencer is pressured by her family to make an important decision.

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.

Hanna worries that her mother is keeping a dangerous secret and is determined to protect her at all costs, which leads to an uncomfortable meeting with Detective Holbrook.

Alison struggles with the death of her mother, as the Liars try to navigate through her new lie.

The Liars try to prove that Alison was involved in Mona's death; Aria worries about her future.

Mona's friend comes to town to pay her respects.

Mona returns to Rosewood in a very fragile state as she must answer to the police for faking her death. Matters only get worse when she is confronted by Lesli’s sister about Lesli’s inadvertent involvement in Mona’s plot. Hanna is determined to help Mona out, not only to reassure her she is safe from Alison but also to try and repair Mona’s friendship with Lesli. Emily tries to help Sara with her troubled home life by encouraging her to explore the possibility of emancipation. Spencer, on the other hand, finds help from someone from her past. Meanwhile, Alison grows closer to Lorenzo as she looks for support outside of her family.