Kandahar, Afghanistan. During the repair of a combat vehicle, a US Army detachment comes under Taliban shelling. Only the sapper of the engineering brigade survives, having received a serious leg injury and having lost his younger brother in that massacre. Two years later, he arrives in Colorado at a ranger training camp to try to pass the difficult selection process and fulfill his dead brother's dream. During the last test, a unit of ranger candidates with special weapons for firing blanks, along with the very sapper who was appointed group commander, is confronted by a huge combat robot of unknown origin, which engages them in ba...