It's every parent's nightmare--getting a call during the school day from their teenager, huddled in a classroom as the sound of bullets echo in the background. When gunmen invade a Brooklyn school, that nightmare becomes a horrific reality. Talking a suspect into sending his hostages out alive is NYPD Detective Gemma Capello's specialty. Alerted to a school shooting at her nephew's high school, she is one of the first officers on-scene. Detective Sean Logan and the Apprehension Tactical Team arrive next and immediately enter the school to apprehend the two shooters, while Gemma remains outside to help students evacuate. But as time stretches on, and there's no word of her nephew, her fear builds that he is one of the lost. Instead of a quickly-resolved mass shooting, one of the two shooters holes up with a group of students and their teacher as hostages, and Gemma steps in to negotiate for their survival. Floors away and armed with only her wits and the sound of her voice to convince him, Gemma fights for control of the situation even as tactical leadership pressures her for a more aggressive strategy. But for Gemma, it's not about a quick solution. It's about moving heaven and earth to bring everyone in that classroom home. And she'll do whatever it takes to achieve that goal.