The young man's newfound deference does something to soothe Mycroft's temper, but it hardly makes him want to figure out how to teach written English to an adult (or even search for the materials to do so). He's not sure anyone could inspire that willingness in him. It's also become apparent that this stranger is foolish as well as uneducated. Mycroft can't remember anyone having ever declared him 'trustworthy' on sight. He's known for being the best of secret-keepers, yes, but he can count on one hand the number of people who may rely on him in a time of need.

"I'm unharmed," he says cooly. "Regarding your... request, however, you must be aware that there are people actually employed by the library for the express purpose of helping visitors find what they are looking for. And that I am not one of those people."