Where else does Louise incorporate secret codes, or hidden messages, into this novel?

The entire Paston Treasure represents a hidden message, literally hidden behind a brick wall in a previously unknown and secret room and filled with Fleming’s taunts and hidden messages to Armand. Fleming, as Robert Mongeau, also taunts Armand with references to what he knows about Armand and his family. He and Sylvie leave clues in the Godin’s home including the book of Ruth’s poetry and the reference to a particular poem, “Waiting” which Armand knows he is meant to recognize. I am certain there are many more examples; they are a reason I enjoy re-reading LP’s books to find the ones I missed. My other example of a secret code is more uplifting; that was Amelia and Armand’s ability to communicate in Morse code, a code known only to them in this case.

Well, the painting in the secret room (as well as the original painting) was chock-full of hidden messages; and the clocks being set to a certain time come to mind. The Mountweasel signature that showed up in various places, hinting, hinting. So many messages diabolically thrown at Armand, waiting to be decoded. Also the significance of wearing those engineering rings, which superficially look plain and uninteresting, but hold such significance through their history and origin. The significance of the 14 white roses at the graduation ceremony at the Ecole Polytechnique sends a message, too. And there was a nauseating secret code attached to the childlike stickers found in the Arsenault logbook. And really, the Three Pines themselves hold a secret code, advertising shelter for those in need. I’m sure I’ve missed several more. This book had a lot of things hidden in plain sight, waiting to be discovered, if only one had the key and knew how to look for them.

To add to Jane’s response was the hidden message Fiona sent to Armand when the Gamache family was being held in their home by Fleming. Fiona pointed to those words written under a rainbow that was drawn by one of Gamache’s grandchildren during the pandemic. She was signaling to Armand that all would be well as she had a plan to help them. The time all the clocks were set for was also a message from Fleming to Gamache. It was the time when Gamache sent him back to prison and would now be the time when Fleming would seek his revenge.

It looks like most of the messages have been mentioned. The shorthand scratched on the elephant and incorporated into the painting was another thing. The obsessed Fleming spent so much time on his plot.

The three pines on the green are a message, that it was safe to settle there. This was said to originate post American revolution days. Then Ruth added to the mystery when she told the story of Anne Lamarque, who after being banished from Montreal, wandered through the ancient forests with her grimoire. Meeting other women, they decided to settle in the wilderness that became the village of Three Pines. They built homes, planted crops, and the three “witches” each planted a pine tree in the clearing. Of course this story can’t be confirmed, but the fact that the grimoire was walled into the loft may be a clue.