The day the bomb threat put the school on lockdown, Gabi was trapped in the girls’ room. It seemed like everything she’d been working for—the AP classes, the college applications—was about to go up in smoke. The police found the bomb in time, but they didn’t find the bomber. He or she could be anyone—one of Gabi’s friends, or the guy she rejected, or the person leaving ominous notes all over the school. It could even be one of the anonymous callers who calls the school helpline where Gabi volunteers. The more messages Gabi gets, the more she suspects she’s part of Stranger’s plan. Could she be the only one who can stop another attack? Or will she be the first victim of Stranger’s revenge?