The warm fall day starts like any other at the Center-a women's reproductive health services clinic-its staff offering care to anyone who passes through its doors. Then, in late morning, a desperate and distraught gunman bursts in and opens fire, taking all inside hostage. After rushing to the scene, Hugh McElroy, a police hostage negotiator, sets up a perimeter and begins making a plan to communicate with the gunman. As his phone vibrates with incoming text messages he glances at it and, to his horror, finds out that his fifteen-year-old daughter, Wren, is inside the clinic.

But Wren is not alone. She will share the next and tensest few hours of her young life with a cast of unforgettable characters: A nurse who calms her own panic in order to save the life of a wounded woman. A doctor who does his work not in spite of his faith but because of it, and who will find that faith tested as never before. A pro-life protester, disguised as a patient, who now stands in the crosshairs of the same rage she herself has felt. A young woman who has come to terminate her pregnancy. And the disturbed individual himself, vowing to be heard.

Told in a daring and enthralling narrative structure that counts backward through the hours of the standoff, this is a story that traces its way back to what brought each of these very different individuals to the same place on this fateful day.