That sort of comment just made Eli want to do all sorts of tests on this man. Constantly compromised by emotion - the things he would be able to observe or tinker with. It wasn't exactly the sort of thing you could ask a person, let alone a complete stranger. Well, at least not without the commitment to go through with it and right now it was just a passing thought.
"That all depends on you now, doesn't it?" He handed the book to the man, not immediately giving any sort of explanation. The page was filled with all sorts of runic spells that could be combined in a way to create a sort of messaging system that when applied correctly could be as discrete or as conspicuous as the user wanted. More importantly once the runes were cast, it didn't take much magic to support it afterward.