At Fort Hood, Soto was greeted by a Viper Company squad leader, Staff Sgt. Nathan Cox. At 32, Cox was older than is typical for his rank. He had a deeply furrowed brow, a hint of graying hair, a college education and an aura of confidence rooted in previous tours in Bosnia and Iraq. He welcomed Soto in a straightforward manner, with a politeness that reflected his Catholic-school years in Iowa. Soto immediately liked him. Cox was a tattooed bookworm with a pensive side. After working under the tutelage of drill sergeants, with their outsize personas, Soto was drawn to his quieter, more composed and reflective demeanor. The platoon sergeant, Sgt. First Class Thomas Wright, assigned Soto as an ammunition bearer in a machine-gun team, a position for an F.N.G. fucking new guy on a fast track to war.