In North Africa, in a detachment of the Legion (the 4th Flag), the Grajo, the legionary more courageous, and Mauro, who just joined, become close friends. Mauro, who only know the name, it seems to hide secrets disturbing. One day when the two friends held a party, an unfortunate circumstance leads to the death of a man. Suspicion falls on Mauro, who stands trial. Meanwhile, the Grajo start to investigate the facts on his own ...