Ryck Lysander has proven himself as a Marine, as a warrior. As he is promoted to sergeant, though, his responsibilities expand beyond merely fighting to leading other Marines into battle. When an old ally becomes a new enemy, one well-equipped and trained, Ryck is pushed to his very limits as he tries to keep his Marines alive while fulfilling his mission of defeating the enemy on the field of battle. Faced with extraordinary challenges and grueling missions, Ryck discovers love, loss, brotherhood, and dogged inner strength as he learns what it means to be a sergeant in the United Federation Marine Corps.