# A trip to the library

I try to go to the library at least once every month, so I've developed a pretty good relationship with the librarian, a nice old man who sometimes teases me about my broad set of interests. Yesterday, for example, I brought him the following books to borrow:

• The Book of Bourbon: How to Brew Your Own Whiskey, by Moses C. Kerne
• Gramática de la Lengua Española, by Lucas E. La Fe
• Secrets of Freemasonry, by Dave Orsini
• Rhine Stones: Sculpture in the Carolingian Empire, by Alden R. Roofs
• Not Playing Fair: Non-Euclidean Geometries, by Vera Allcub

He looked at the books quizzically and smiled at me:

"You know what?", he said, "I have one right here that I think you'll love. Take it home". He reached for it. Its name was Life in the Weimar Republic: 20 Essays, by Gerr Hinder. I was unconvinced, but he insisted. "One more book won't hurt!"

I sighed and added the book to the pile. The librarian started laughing as I handed him the library card, and mysteriously said: "That was a good game, if a bit short. Maybe you'll win next time."

What was the librarian talking about?

Edit: I removed the pattern tag (I thought about it and it doesn't really fit) and replaced it with a cipher one, which should help.

Hint 1

I came back to the library, and was greeted enthusiastically by the librarian. I still hadn't finished the six books I took home, but a couple of subjects had piqued my interest in the meantime.

"Hey!, I said, "Can you recommend me anything to read about Zoroastrianism? Or Kantian epistemology?"

"Lots of stuff", he replied. "But, after our little exchange last time, I'm afraid those are off-limits".

"What do you mean? Did I do something wrong?", I asked, a little scared.

"Oh, no, not really. But if you want to play again, you'll have to pick something from the Technology aisles".

I didn't want to make an enemy of the librarian, so I decided to humor him. I chose The 100 Most Useless Patents Filed in the U.S., since it seemed to be an easy read. But when the librarian saw it he sighed and said, "oh, not that one".

Hint 2 (not much of a hint, really)

The puzzle is almost solved, with only the deciphering (actually decoding if that helps) part remaining. Once that's done, the game that's taking place should be obvious. Think about why a Technology book is required to start the game anew.

Hint 3 (some story)

I spent much of the week trying to find out how to play the game the librarian was referring too. I had an idea of what game it was supposed to be, but how the books could contain the information to play it was still a mystery. I came back to the library and leaned towards the old man's desk, whispering. "So... 794, right?"

The man laughed and replied, "Right. But I don't know if reading any of those would help". He saw the look of confusion on my face, so he added: "Different rules, you fool!".

"How so?", I asked.

"To begin with, last time we didn't really play, I just made one last move. Half a move, actually, didn't have much of a choice."

"Look, I don't even know how to make moves. So maybe let's start with that."

"Oh, you should head out to the 00x then, mate!. The table should be in some book there. Then when you're ready to start, bring me two books. Then I'll give you two back and so on."

"First one should be a Technology one, right?".

"Or something about the Greek language if you're feeling adventurous...". He scratched his head, like he had forgotten something. "Right, I didn't tell you about the name changes. That one should be obvious enough, and you won't need the other one anytime soon. I hope so, anyway. Good luck!"

About this hint: most parts about the "gameplay" aren't important to solve the puzzle, they're just there to make it a little bit more consistent (and probably more confusing, too). Just focus on:

where you could find the decoding system inside the library, and maybe the 1 book = half a move part.

Update: Figured it out! They are playing:

Chess. The Dewey Decimal Codes put together in pairs of two represent chess moves when converted from Hexadecimal to Characters

66+34 = f4
65+36 = e6
67+34 = g4
51+68+34 = Qh4

The first three moves (plus the optional 4th by the Librarian) represent Bird's Opening

Explanation of Hints

Technology Book: You need to start with a technology book as the possible opening moves are for the pawns which are denoted by small letters a-h, which are Hex values 61-68 (or 61x to 68x in Dewey Decimal for this puzzle)

Here's my initial thoughts if it helps kick this off:

It could be related to the Dewey Decimal System
The books in order would correspond to these codes

663 Beverage Technology $$\rightarrow$$ The Book of Bourbon: How to Brew Your Own Whiskey
465 Grammar of standard Spanish $$\rightarrow$$ Gramática de la Lengua Española
366 Secret associations & societies $$\rightarrow$$ Secrets of Freemasonry
734 Sculpture from ca. 500 to 1399 $$\rightarrow$$ Rhine Stones: Sculpture in the Carolingian Empire
516 Geometry $$\rightarrow$$ Not Playing Fair: Non-Euclidean Geometries

Librarian's Response:
834 German essays $$\rightarrow$$ Life in the Weimar Republic: 20 Essays

Hint 1
295 Zoroastrianism $$\rightarrow$$ Zoroastrianism
121 Epistemology (Theory of Knowledge) $$\rightarrow$$ Kantian epistemology
608 Patents $$\rightarrow$$ The 100 Most Useless Patents Filed in the U.S.

• I suspect 366 not 209 and 734 not 733; and I think 943 not 834 (but could be wrong about that). And my guess is that the problem with 608 is the zero in the middle. – Gareth McCaughan Aug 19 '19 at 12:10
• (None of this guessing makes the next step obvious to me, though the kind of thing we're looking for seems clear enough.) – Gareth McCaughan Aug 19 '19 at 12:10
• @GarethMcCaughan those were my thoughts when posting, just hoping to give someone more clever than I a kickstart! – bhooks Aug 19 '19 at 13:01
• Implemented the first two corrections, and updated the first code. Did not change 834 to 943 – bhooks Aug 20 '19 at 12:34
• Also updated the formatting and added more possibilities based off Hint 1 – bhooks Aug 20 '19 at 12:40

I assume there is something more to this, but the authors' names can all be

anagrammed to various synonyms of red herring:

1. Moses C. Kerne $$\rightarrow$$ SMOKESCREEN
2. Lucas E. La Fe $$\rightarrow$$ A FALSE CLUE
3. Dave Orsini $$\rightarrow$$ A DIVERSION
4. Alden R. Roofs $$\rightarrow$$ FOOL'S ERRAND
5. Vera Allcub $$\rightarrow$$ A CURVEBALL

And, of course, Gerr Hinder $$\rightarrow$$ RED HERRING

• You are correct by all accounts, because there is something more to it. This just means rot13(gur anzrf bs gur nhgubef ner veeryrinag) – NudgeNudge Aug 14 '19 at 15:05
• @NudgeNudge Yeah, that's what I figured... I thought I'd post this since I went to the trouble of figuring it out, and to prevent others from wasting their time going down the same road... – GentlePurpleRain Aug 14 '19 at 15:06
• I hear your concern. I feel like this is a legitimate "partial answer", as it explores and eliminates one particular potential solution path. But I'm open to other opinions. If others feel it should be deleted, I'm down with that. – GentlePurpleRain Aug 15 '19 at 5:19
• As far as I can see, this doesn't add anything to OmegaKrypton's and msh210's observations, which were posted to the question as comments (the proper way to post non-answers) more than an hour earlier. – Bass Aug 15 '19 at 10:41
• It does add one thing, namely finding all the anagrams and thereby assuring us that all the author names are likely irrelevant. Otherwise it could have turned out, e.g., that what we're trying to do is to find books whose titles match up somehow with all of a set of things associated with one author's name. Not very likely, but not impossible. And having spent a few minutes anagramming names and not having found all of them, I'm grateful for having that line of attack definitively closed down. – Gareth McCaughan Aug 15 '19 at 18:25