How We Fall Apart by Katie Zhao

Nancy Luo is shocked when her former best friend, Jamie Ruan, top-ranked junior at Sinclair Prep, goes missing, and then is found dead. Nancy is even more shocked when word starts to spread that she and her friends–Krystal, Akil, and Alexander–are the prime suspects, thanks to “the Proctor,” someone anonymously incriminating them via the school’s social media app.

They all used to be Jamie’s closest friends, and she knew each of their deepest, darkest secrets. Now, somehow the Proctor knows them, too. The four must uncover the true killer before The Proctor exposes more than they can bear and costs them more than they can afford, like Nancy’s full scholarship. Soon, Nancy suspects that her friends may be keeping secrets from her, too.