Board Thread:Speculation House/@comment-14909251-20140726050227/@comment-24994749-20140726054245

He acted uncomfortable since the moment he saw Emerald and Mercury, as if he had and educated guess of who they were but wanted to see if he could get away by playing fool. When she says Third Crusade he reacts as if it was a confirmation of his original suspicion. The book might or might not exist, but I think that if it isn't a code used by White Fang members to identify each other, it's at least a significant historical event related to faunus history.