Fridge / The Valley of Fear

• Cryptography in the very beginning of the novel makes sense only from the Doylist perspective (to show off Holmes' code-breaking abilities). As it is Moriarty, not the police, who Porlock is afraid of, and as he fears for his life much more than cares about the task assigned by Holmes, it is extremely doubtful he would use any cypher in the first place: Moriarty would execute him for the very fact of spying, regardless of what exactly he managed to convey - and, moreover, the presence of the unciphered keywords "Douglas" and "Birlstone" would allow him or his minions to easily guess the approximate contents of the message anyway. Even less explicable is the second letter from Porlock - instead of detailing why he wouldn't send any more messages, he would spend just about the same amount of time and risk simply finishing the code, especially given that a simple mention of the title of the book in question looks much more innocent than an obviously encrypted message.