After obtaining the short sword of morin, head to lesser faydark and find Bryn Fynndel. He will be located just outside the Ranger Encampment, near the Teir`Dal camp. Hailing does not work, but if you say "Morin sent me to find you" he will respond. He wants you to obtain an codebook from a shadowed man. This is as far as I've gotten, as none of the shadowed men seem to be dropping the thing... :-s