10:00 a.m. The principal of Opportunity High School finishes her speech, welcoming the entire student body to a new semester and encouraging them to excel and achieve. 10:02 a.m. The students get up to leave the auditorium for their next class. 10:03 a.m. The auditorium doors won’t open. 10:05 a.m. Someone starts shooting. Told from four different perspectives over the span of fifty-four harrowing minutes, terror reigns as one student’s calculated revenge turns into the ultimate game of survival.