[3] At Bayview High, Bronwyn, Simon, Nate, Cooper, and Addy attend detention with teacher Mr. Avery after he found mobile phones in each of their school bags, against his strict no-phone policy.

He drinks tap-water from a plastic cup and suffers a fatal allergic reaction due to his peanut allergy.

Each of the secrets would affect the students' future: Bronwyn's cheating in chemistry class could impact her college applications; Nate's repeated misdemeanor could send him to jail; Addy's infidelity might end her relationship with Jake; and the accusation of steroid use could halt Cooper's potential baseball career.

After Simon's funeral, his post is leaked and the rest of the school learns the four's secrets, triggering the consequences: Bronwyn's parents are disappointed, Nate's house is searched for drugs, Addy's relationship ends, and Cooper's performance is investigated.

When Cooper is bullied verbally in the cafeteria after this news is leaked, Nate defends him, and the group sits together, demonstrating their new solidarity and friendship.

Bronwyn contacts Eli Kleinfelter, a lawyer she saw on television defending the Bayview Four on the crime show Mikhail Powers Investigates, asking him to help.

Janae accepts a plea bargain for her involvement, and Nate is released but is shaken from his time in the juvenile detention center, rejecting Bronwyn's concern and breaking off their relationship.

Reception of One of Us Is Lying has been mostly positive, receiving multiple awards and nominations, primarily within the Young Adult category.

[5] USA Today said "This is no ordinary whodunit, and the author finds a way to make the resolution both surprising and relevant.

It also mentions how, although Bronwyn, Maeve, and their father's side of the family are Colombian, the cast is predominantly white.

[22] Set 18 months later, the novel follows the residents of Bayview as someone starts playing a sinister game of truth or dare.