Gabriella Mallory, AP student and perfect-daughter-in-training, stands barefoot on a public toilet for three hours while her school is on lockdown. Someone has planted a bomb and she is hiding. The bomb is defused but the would-be-bomber is still at large--and everyone at Central High School is a suspect. The school starts a top-secret crisis help line and Gabi is invited to join. When she does, she is drawn into a suspenseful game of cat and mouse with the bomber, who has unfinished business. He leaves threatening notes on campus. He makes threatening calls to the help line. And then he begins targeting Gabi directly. Is it because her father is the lead police detective on the case? Is the bomber one of her new friends? Could it be her new boyfriend with his complicated past? As the story unfolds, Gabi knows she is somehow connected to the bomber. Even worse, she knows she is part of his plan. Can Gabi reach out and stop him or will she be too late?