the gravity of the role weighs heavy on michael kelley, who is playing then-lieutenant colonel gary valeskilease bring my baby home. >> i promise you, every man is coming back safely. >> how can you promise that? >> because i believe that too and because it's my responsibility. >> we wanted to -- the men who did this in real life, the justice that they deserve. so i think that part is really special. that's what i think the heart and the care comes from. >> reporter: the man michael kelley is portraying now a three-star general. gary veleski perfectly captured that heart and care all those years ago. >> uncommon valor was common that day. because there but you don't teach stuff like that. you can get them to that point, but where they go in combat where when those rounds are being directed at them, how they react, you know, no one knows until it happens. and they all just performed magnificently. so, you know, i'm honored to be able to serve these soldiers like that. >> reporter: for "nightline," i'm martha rad dates in ft. hood, texas. >> "the long road home" can be seen on tuesday nights