Emma Wilson left Warren Academy after her diary was posted at Homecoming last year. Just when the school thought they had moved on, a letter from Emma has turned up. She vows to take revenge on her former friends until the person who stole her diary confesses. But who did it?

After a year, nobody has confessed to stealing Emma's diary. Suddenly, Warren Academy students realize, their secrets might just come out, as well. Maybe a certain player isn't exactly who they claim to be?

It's a new day at Warren Academy and Alex, Charlie, and Jake learn that a certain someone may be back in town. Also, the student body discovers that one of their fellow classmates may not be as nice as they seem.

Class President, Preston, may not be as perfect as he seems. In the latest Warren Academy gossip, Emma reveals Preston's darkest secret. Meanwhile, Principal Lee wants to save Warren Academy's reputation and is desperate to put an end to the drama. She asks Charlie to help her find the person that stole Emma's diary in exchange for a glowing scholarship letter. But Charlie may now be the next victim of Warren Academy's gossip...

It’s Tatiana’s birthday and she’s in for a big surprise…

After Alex's mural gets vandalized, Principal Lee gives the group a day to come clean about who stole Emma's diary or else everyone gets suspended. Charlie doesn't want to lose her chance at getting a scholarship and is determined to find out who did it. As she starts investigating, her secret gets aired out...

Emma exposes personal information about Tess, prompting Tess to make her own confession. Concerned for Alex's future, Charlie takes things into her own hands by pressuring Tatiana with the picture of her at Mary Rogers Clinic. But Charlie has her own confession to make...

Charlie confesses to Jake, Tatiana and Preston. Charlie and Jake track down Emma, and some shocking news is revealed about Alex.

It's the season finale, and the truth finally comes out at Homecoming but nobody is prepared for what is revealed. How will the group respond when a friend holds everyone's futures in the palm of their hand?

Colvin College is still reeling from the fire that destroyed the administration building last semester, and put a student, Margot Miller, in a coma, when Professor Moynihan announces he will be offering his famous “History of Lying” seminar to a select number of students. Cat Carlson is thrilled to be accepted into the course: Moynihan is a celebrity on campus and is releasing his very own lie-detecting technology, CUFF, later in the year. But the class—“The Liars' Club”— discovers Professor Moynihan has his own agenda.

The game is afoot! Cat begins her investigtion with her best friend and podcast co-host, Allie. They look over Allie’s super-helpful, super-pink suspect board, which ranks the other Liars Club members' alibis by how suspicious they are. They realize that Naia's alibi is really weak. Not only that, but Allie points out that they don’t know why the professor is so sure the fire was arson. Steeling herself, Cat decides to confront both Naia and Professor Moynihan about their secrets.

Moynihan puts everyone’s truth-telling abilities to the test, literally, with a pop quiz experiment that reveals the biggest fibbers in the class. Uncertain how to navigate the treacherous course, members of the class begin forming tentative alliances. But can anyone be trusted in the Liars’ Club?

The students show up to class only to discover that they have been invited to a cocktail party at the Professor’s house. Their invitations contain secrets— ones that they are not allowed to share with anyone else. Of course, the Party Twins and Alvaro alliance immediately breaks the rules. Once at the house, the Liars Club discovers that their task is to return that secret to its rightful owner, forever binding them together. When Bella and Benedict’s cheating is revealed, however, more secrets spill forth.

While Moynihan expresses his confidence in Cuff to a local journalist, Cat’s is badly shaken. She discovers Allie and Harper confiding in each other about the Liars’ Club case and feels betrayed by her only friend. Left vulnerable and even more alone, Cat becomes the prime suspect when a video of her actions the night of fire is emailed to every student on campus.

The Liars' Club gets a chance to use Cuff on each other, testing the truth of their alibis. Things go askew, however, when the device proves Erika’s honesty: she was outside the administration building at the time of the fire, and she saw someone who looked like Wilson running away. Adding to the upheaval is Margot Miller’s recovery from her coma. Suddenly, there’s someone else who might have information about everything leading up to the fire. The Liars' Club may have narrowed down their suspect list, but the mystery is far from being resolved.

Margot Miller is awake—but isn’t taking visitors. That doesn’t stop Harper, though. When she finds out that she’s not the only Liars' Club member who snuck into the hospital, she goes to talk to Cat to share what she knows. But when The Colvin Cauldron publishes a shocking story about Allie, Cat realizes she may not have all the facts.

Wilson meets Cat in the studio where she emerges and ties Wilson up in an effort to force him to confess to the fire. Cat and Allie begin to interrogate Wilson. Through their interrogation, the three realize that...