Don't Even Think About It by Sarah Mlynowski (Delacorte Press hardcover, 11 March 2014).
In this quirky story, most of the members of Bloomberg High School homeroom 10B go to the school nurse for 'flu shots at lunchtime.
Of the 23 students in the class, only one refused to get the shot for reasons of disbelief.
The next day shy Olivia Byrne is due to give a speech in her public speaking class, and she's terrified. Standing in the front of the room, she feels dizzy and ill. Suddenly she hears her friends saying things like "Is she going to pass out?" and "What's wrong with her?" That's when she realizes that they are not actually speaking. She can hear what they are thinking. She faints.
Slowly, the remaining students in 10B come to the same realization: they can hear other people's thoughts. Pi Iamaura, so dubbed because she could quote the first thirty-nine digits of π, realizes it first while doing her morning swim at the community pool. She thinks that the person in the lane next to her is talking to her, but when she responds, he just looks at her strangely. When she realizes that his lips weren't moving, it dawns on her that she actually heard his thoughts.
Arriving at school, she discovers that other kids in the class are experiencing the same phenomenon. They get together after school and decide not to tell anyone about it for the time being. Over the next few days and weeks, all the students from 10B (except for doubting Renée) are telepathic.
Afraid of what might happen if the news goes public, they decide to keep it to themselves, and discover that knowing what other people -- even strangers -- are thinking is not necessarily a good thing.
The story does not resolve as expected. At least, not as this reviewer expected. And although there are so many characters, a cast list would be helpful, it's a quick, enjoyable story that keeps the reader guessing until the very end.
FTC Full Disclosure: Many thanks to Netgalley and the publisher for the e-galley.