Alison was sent to The Preserve at Addison-Stevens, a rehab facility for mentally ill patients, which she believed was the Liars' fault, and has been plotting revenge ever since.

Subsequently, Courtney morphs into "Queen Bee Ali" and, out of pure chance, befriends the Liars up until the night of her infamous disappearance when she was killed and buried by the real Alison DiLaurentis and her accomplice Nick Maxwell.

She also has a strained relationship with her boyfriend, Sean Ackard, due to his virginity club vows and is arrested after taking and accidentally crashing his father's car, causing them to break up.

Hanna battles the urge to turn back to bulimia, struggles with living with her absent workaholic mother, and manages the stress of keeping her queen bee status.

Throughout the story, the liars get messages threatening to reveal their secrets of the present and past, including a terrifying incident the girls refer to as "The Jenna Thing".

Now homeless after being kicked out by her mom for hiding her dad’s affair with his student Meredith for years, Aria goes to live with her new boyfriend, Sean Ackard.

Then she looks at the homemade videos that she made years ago to realize that Alison was also "dating" Ian, Melissa's boyfriend on whom Spencer had a crush (and had also kissed).

The girls recognize it is A from the eerie text: She Knew Too Much -A Emily's parents catch her with Maya at a party and send her to Iowa to live with her strict, religious relatives.

After a shock at her gran's will reading and her family neglecting her, Spencer comes to believe that she is adopted and starts searching a reuniting website for answers.

Spencer meets a woman named Olivia Caldwell who she thinks is her real mother, and attempts to move to New York, but it turns out to be a scam and she loses her college money.

Aria invites Jason to a party at Radley, a children's mental hospital turned hotel, but he accuses her of playing a cruel prank on him and runs away.

Throughout this, Emily has constant run-ins with an erratic Jason who almost runs her over and she receives many instructive texts from A who sends her pictures and questions to figure out Alison's murder.

"A" sends Emily to an Amish group in Lancaster, under a false identity, where she befriends a girl named Lucy and helps her plan an upcoming wedding.

Emily discovers Wilden was Leah's boyfriend and believes she is the body in the grave not Alison's, and A instructs her to break into Rosewood's police precinct for evidence but she is caught and arrested.

Hanna's father sends her to a clinic to prevent her eating disorder from reappearing due to stress, where she befriends a controlling girl named Iris.

They're able to escape after stumbling onto Ian's body hidden in a closet and releasing a bound Melissa, who Ali had kidnapped and was planning to kill as well.

Patrick, somebody who's helping out at the set, offers Hanna a modeling job, but he takes some naughty pictures and threatens her with them, saying he will release them to the public and ruin her dads' chances of becoming senator, unless she gives him $10,000.

Emily's girlfriend Jordan, who is in prison, is told by her lawyer there is a way to leave on parole and both are ecstatic and begin making plans for a future together.

Using the receipt Emily snatched, the girls track down a pool house on one of Nick's parents' properties that they believe Ali had been hiding out in.

During an event to honor disadvantaged Rosewood youth, all the girls leave early to return to the pool house to find it covered in blood.

Hanna and Spencer get into a huge argument, eventually Aria gets involved and the three end up blaming Emily's death on each other and saying extremely hurtful things.

After realizing that his girlfriend could be facing prison for life, Mike decides to propose to Hanna and they begin going crazy trying to plan a fabulous wedding in such a short space of time.

Realizing that Mrs. D had been protecting Ali and putting all clues together Emily called the police and began a conversation with Mrs. D about how she knew she was keeping Alison hidden in her home.

Set between Unbelievable and Wicked, the book is told from the point of view of the second "A", Alison DiLaurentis, as she spies on the girls during their Christmas vacation.

Spencer and Melissa decide to team up to get revenge on Colin by putting crushed Viagra in his Aminospa vitamin water right before his important tennis game.

After competing for Vince's affection, she and Dinah become friends after catching Kate making out with the mall's new Santa (prior to Emily), something which Hanna also photographs.

As they watch TV, it shows that Halbjorn has been caught, and it also reveals that he's done these sorts of things in the past, including trying to blow up a demolition office.

She then sees Emily, Hanna, Spencer and Aria arguing and goes out to talk to them causing her parents to believe she is actually Alison and send "Courtney" back to the mental hospital, unknowingly switching the two.

Alison and the mysterious figure begin to fill the hole and just as she suffocates to death Courtney recognises the accomplice, last thinking "why?"

Note: This book is titled Ali's Pretty Little Lies but it's actually about her twin sister, Courtney, who pretended to be Alison because she didn't want to go to a psych ward.