Brady McCall and Franklin T. Stilwell, aged 10 and 15, witnessed their families die in a brutal attack. Orphaned and alone halfway across the frontier, with no time for mourning and only their horses for a lifeline, the boys embark on a journey that spans half a century. As old men, they reflect back on a friendship forged in blood and tempered in honor, and plan one more grand crusade before going quietly into a life where only memories define who they are.