In the city of New Orleans, police officers, fire fighters, and emergency medical technicians working the overnight shift answer as many as a thousand emergency calls every night. Early in this shift, a fleet of police cars and ambulances respond to a report of a man discovered in the street bleeding from multiple gunshot wounds. EMTs Holly and Gavin work furiously to keep the victim alive, rushing him to the hospital, while police flood the neighborhood investigating the shooting and trying to prevent retaliation.