Derrick Shimmons is the manager of security at Christ Memorial Hospital. He is a former Marine that spent time in Afghanistan. His confidence has taken a huge hit from his time in the Marines due to people making fun of him and things happening against him.
He turned his experience in the military into a career in security once he got out. Now he is in charge of many people and an entire department. If he can keep doing everything right.
Terrorists target the hospital for revenge against Americans for leaving Shiite Muslims to fend for themselves after Operation Desert Storm. The main villain has been in the country for decades and has worked to become a doctor. He keeps himself hidden and has been seething the entire time. When the attack he has been planning for decades begins, he stays idle among the hostages for hours and comes out only when things start going bad.
Derrick must first navigate his own mistakes and problems, then protect the people of the hospital during the attack. He puts together a small group of people including security personnel and hospital visitors. He relies on a female active duty infantry leader who has jumped hurdles to get where she is today. She has come home to visit her mother in the hospital.
Most characters in the novel are around long enough for the audience to get invested in, and then they are killed off throughout the book. Derrick has to lead a delaying fight toward the roof to evacuate people to keep them safe and grow as a person.
All this leads to a climactic ending on the roof between the two leaders. The ending of the book leaves the reader wanting more, and then Derrick and Meghan secretly take the leader of the terrorists to the CIA for answers, leaving the opening for another book.