Another complicated installment in the August Dupin series. In fact, it is probably the most complicated of them all.

And that’s appropriate given the theme of encryption. Like the concept of the bibliomania in The Mad Trist and the egregore in The Quintessence of August, Stableford explores multiple meanings of a word, sometimes through non-humorous puns.

Encryption isn’t just something your computer does when you’re buying a copy of, say, a Stableford novel online. It also means to bury, to embed and conceal information in another form, and, if you’re a Pythagorean philosopher, everything you perceive is the encryption of an ultimate reality.

Here encryptions take the form of mysterious tattoos and coins, chants of South Sea Islanders, the legends of the sunken city Lys, the Breton version of the King Arthur story, fairy lore, and Shakespeare’s A Midsummer Night’s Dream.

The story starts about two months after the previous book in the series, The Quintessence of August. It does indeed have Cthulhu and piracy of the normal sort as well as metaphysical.

Things kick off when a minor character of the series so far, Dr. Chapelain, who works at a local mental asylum, tells Dupin about the strange delusion of one of his patients. She believes she lived in the court of King Oberon once, and Chapelain, who is really Merlin, is there to take her back. In reality, Chapelain thinks she a woman of around 40 near death after a life as a streetwalker. As an experiment, Chapelain has been mesmerizing the woman to see if he can treat her via mesmerism. She has an odd marking on her back, not exactly a tattoo, that looks like writing.

Dupin isn’t really interested in this until he hears the woman’s name, Ysolde Leonys. A bibliomaniac named Breisz from Brittany has been asking around for various materials related to a pirate named Taylor, the Levasseur cryptogram, and anything to do with the name Leonys. Levasseur was a real pirate operating out of the Indian Ocean in the early 18th century. Before being hanged in Paris, he threw a coin into the crowd claiming the cryptogram on it was the key to locating a treasure. And it sounds like the markings on Leonys’ back relate to that cryptogram.

And in the treasure of Levasseur may be John Dee’s translation of the Necronomicon.

And so the adventure begins which will find shoggoths walking about Paris, references to the narrator’s friend Edgar Allan Poe and his The Narrative of Arthur Gordon Pym, mention of another possibly encrypted legend in Samuel Coleridge’s “The Rime of the Ancient Mariner”, and a climax that could be Stableford’s gesture not to H. P. Lovecraft but William Hope Hodgson. There’s also a whole lot of pirate treachery.

Along the way are discussions about whether fiction itself is dangerous.

Dr. Chapelain is not the only minor series character to move to the foreground in this story. So does Dupin’s fearsome housekeeper Madame Amélie Lacuzon. People have called her a witch for a long time for her protective ways in regards to Dupin, but maybe she really does have strange powers. And, of course, Comte St. Germain is an important character too.

.As usual with this series, I have said enough, indeed, perhaps too much in preserving Stapleford’s surprises. If you like the Cthulhu Mythos mixed with philosophy and history, this is definitely the book for you. ( )