Graff and the other leaders of the school covertly work to isolate Ender from his fellow recruits and prevent him from growing too comfortable in his environment. The cadets participate in competitive war simulations in zero gravity, where Ender quickly masters the game and dominates his opponents. The school continually tries to break Ender down, first promoting him to command a new army composed of raw recruits, then pitting him against multiple armies at once, but Ender's success continues. Ender's jealous ex-commander, Bonzo Madrid, draws him into a fight outside the simulation, and once again seeking to pre-emptively stop future conflicts Ender uses excessive force, and like Stilson before him Bonzo dies from his injuries.