A kid dies in detention with four other kids. They become suspects in his murder because he was a giant dick.
Karen M. McManus's book about death and bullying starts off the Breakfast Club but ends near Lifetime movie territory. Bronwyn (Brain), Simon (Dead Guy), Nate (Criminal), Cooper (Jock), and Addy (Princess) are all sent to detention. They claim to have been framed, the phones in their bags not theirs. Maybe not Nate because he deals drugs and stuff and has multiple phones. Also Simon who takes a drink of dosed water and dies from a nut allergy. Seems somebody hated him enough to know his fatal weakness. After the police begin to suspect the crew, each student and their friends and families have their secrets freed. Addy and Cooper each belong to the popular crowd that Simon despised when they rejected him. Bronwyn and her friend once messed up Simon's chance at joining a premier school event. Nate just sells drugs. Each of them has other secrets on top of the ones listed, making them all pretty good suspects if beholden to the character traits those secrets give them. Well rounded but at times rather boring. As the tension grows, the brain and the criminal grow closer. She lets go of her more tight-assed ways, as does the princess, while the guys grow more sensitive and reliable. Cooper's life gets the most readjustment as the story goes on, leaning on heavy tropes of sexual awareness better told in But I'm a Cheerleader. The princess Addy becomes more of a self-assured badass after realizing her asshole boyfriend doesn't have to be her asshole boyfriend. Things come to a head as each kid confronts their fears. One of Us is Lying answers the question "What if Agatha Christie had written the Breakfast Club" that no one was asking.
Too bad a lot of the pat storytelling of teen drama overshadows a lot of interesting character development.