paul fairbrook helped write this compact manual-- known as the red book-- which outlined in great detaillly every nazi unit, information every ritchie boy committed to memory. >> fairbrook: when the soldiers said, "i'm not going to talk," they could say, "wait a minute. i know all about you. look, i got a book here, and it tells me that you were here and you went there and your boss was this." and they were impressed with that. >> wertheim: so it sounds like this gave the officers in the field a guide to the german army so they could then interrogate the german p.o.w.s more efficiently. >> fairbrook: that's exactly right. >> wertheim: the ritchie boys earned a reputation for delivering important tactical information fast, making a major contribution to every battle on the western front. their work save lives? >> frey: absolutely. they certainly saved lives. i think that that's quantifiable. >> wertheim: david frey teaches history to cadets at the u.s. military academy at west point. >> frey: part of what the ritchie boys did was to convince german units to surrender without fighting. >>