After a lifetime of being bullied, Daelyn is broken beyond repair. She has tried to kill herself before, and is determined to get it right this time. Though her parents think they can protect her, she finds a Web site for "completers" that seems made just for her. She blogs on its forums, purging her harrowing history. At her private Catholic school, the only person who interacts with her is a boy named Santana. No matter how poorly she treats him, he just won’t leave her alone. And it's too late for Daelyn to be letting people into her life...isn’t it?

Fifteen-year-old Jeff wakes up on New Year’s Day to find himself in the hospital—specifically, in the psychiatric ward. Despite the bandages on his wrists, he’s positive this is all some huge mistake. Jeff is perfectly fine, perfectly normal; not like the other kids in the hospital with him. But over the course of the next forty-five days, Jeff begins to understand why he ended up here—and realizes he has more in common with the other kids than he thought.

Biz knows how to float. She has her people, her posse, her mom, and the twins. She has Grace. And she has her dad, who tells her about the little kid she was, and who shouldn't be here but is. So Biz doesn't tell anyone anything. Not about her dark, runaway thoughts, not about kissing Grace or noticing Jasper, the new boy. And she doesn't tell anyone about her dad. Because her dad died when she was seven. And Biz knows how to float, right there on the surface - normal, okay, regular, fine.

Ambitious New York City teenager Craig Gilner is determined to succeed at life-which means getting into the right high school to get into the right college to get the right job. But once Craig aces his way into Manhattan's Executive Pre-Professional High School, the pressure becomes unbearable. He stops eating and sleeping until, one night, he nearly kills himself.

Theodore Finch is fascinated by death, and he constantly thinks of ways he might die. But each time, something good, no matter how small, stops him. Violet Markey lives for the future, counting the days until graduation, when she can escape her Indiana town and her aching grief in the wake of her sister's recent death. When Finch and Violet meet on the ledge of the bell tower at school, it's unclear who saves whom.