The Vivaldi Cipher

A Vatican Secret Archive Thriller - Book 1 (Sequels to The Magdalene Chronicles series)

During the election of a new Pope in the mid-18th century, famed violinist Antonio Vivaldi learns of a ring of art forgers who are replacing the Vatican’s priceless treasures with expertly-painted fakes . . .

Desperate, the composer hides a message in a special melody, hoping someone, someday, will take down the culprits . . . 

Nearly three hundred years later, the confession of a dying Mafia Don alerts a Venetian priest to a wealth of forged paintings in the Vatican Museum, and the key to their identities lies hidden in a puzzling piece of music. Father Michael Dominic, prefect of the Secret Archives, investigates, and is mystified when he finds a cipher in an old composition from Vivaldi. Desperate to stop this centuries-long conspiracy, he calls on fellow sleuth Hana Sinclair and Dr. Livia Gallo, a music cryptologist, to help him crack the code and learn the truth.

But the Camorra, a centuries-old Italian Mafia clan, won’t stand by while some interfering priest ruins their most lucrative operation. Along with a French commando and two valiant Swiss Guards, Dominic explores the dark canals and grand palazzos of Venice to uncover the evidence he needs to stop the sinister plot. Can he unearth it in time, or will the Church’s most valuable artworks fall prey to this massive conspiracy?

If you love James Rollins, Steve Berry, and Lee Child, you may lose sleep over this impossible to put down thriller! Packed with historical events and non-stop action, readers will be burning through pages late into the night. McAvoy’s fans say his “attention to detail makes the story utterly believable, leaving the reader wondering what is real and what is fiction.”

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1st Place Prize Winner
(Religious Fiction category)
Next Generation Indie Book Awards 2022

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Critic’s Review

McAvoy’s plot melds art, music, and ciphers into a century-spanning, edge-of-your-seat heist. Historic and modern clues meld together perfectly, and the complex workings of church and mob hierarchies combined with character relationships elevate the story. McAvoy’s prose is both clear and direct, serving the story well. Clever dialogue and unique character voices make the novel shine even brighter.

A fun, exciting look at a centuries-old art scam sets the church and the mob at odds, weaving historical figures and wonderfully crafted characters together in a sweeping mystery/thriller sure to appeal to fans of the genre. Father Michael Dominic is a complex protagonist, grappling with his emotions as well as mysteries that need unfolding and an angry mob boss. Antagonist Don Angelo Gallucci proves a classic villainous mob boss. — The BookLife Prize 2021

“Gary McAvoy returns to continue building on his previous series, though the shift away from all things Magdalene has not lessened the impact of the writing. There is still a great deal to discover in the Secret Archives of the Vatican and who better to bring them to light than Father Michael Dominic. It was during the election of the new pontiff in the mid-18th century that famed violinist Antonio Vivaldi came to learn a dreadful secret, one that could scandalize the Holy See for centuries. Using his skills in musical composition, Vivaldi hid a message in his music, hoping that it would be found and those responsible revealed. Today, Father Dominic comes upon one of these compositions and enlists some help to crack the code. Soon, a long-held secret that will surely tarnish the Vatican comes to light. However, its revelation comes at a price, specifically the ire of a powerful branch of the Italian mob. Dominic will have to stay one step ahead of these ruthless men to ensure the truth is revealed, but staying alive may be a larger concern.

While many would expect the election of a new pope to be a wonderful thing, the papal concave of 1740 held more problems than simply who would be the best candidate. Cardinal Pietro Ottoboni, the obvious front-runner is poisoned, holding onto the knowledge of something sinister. He confesses to Antonio Vivaldi, the famed violinist of the time, on his deathbed. Worried that his own life could be in danger, but refusing to sit on the secret, Vivaldi weaves a cipher into some of his manuscripts, in hopes that someone will learn the truth about the artwork scattered throughout the Vatican collection before it is too late.

In present day, a priest takes a confession of a dying mafia don, one who has chilling news about the Vatican’s art collection. This stirs up some curiosity, which is furthered when curator of the Vatican’s Secret Archives, Father Michael Dominic, stumbles upon one of the Vivaldi compositions. With the help of Hana Sinclair, a sharp-witted journalist, and a famed cryptologist, Dr. Livia Gallo, they all learn the message Vivaldi wished to broadcast. It would seem much of the artwork within the Holy See is forged and a powerful mafia organization, the Camorra, continues to run the ring to this day.

Dominic, Sinclair and Gallo slowly uncover the truth, which leads them to one of Vivaldi’s descendants, Contessa Donatella Vivaldi herself. While visiting the woman in Venice, much is revealed and truths begin to emerge. However, this is only the beginning, as the Camorra cannot have their operation foiled or the truth about the secret come to light. It’s been running smoothly for centuries and some meddlesome priest will not halt the lucrative business because he wants to ‘do right’ with his employer.

Dominic and Sinclair enlist the help of their friends in the Swiss Guard to delve deeper and uncover those responsible. This is no small feat and it’s soon discovered that with such secrets come battles to the death. As Dominic pushes ahead, his mettle is tested, particularly when Hana is captured and assured she will die. While most of the art world is none the wiser, Father Dominic must risk it all for the woman who is a friend and a truth that must come out! McAvoy picks up just where his past series ended with this chilling piece that I could not put down, no matter what obstacles tried to find their way in my path.

It was just last summer that I discovered the work of Gary McAvoy and I have not been able to say enough about him since. Using a backdrop of the Vatican, McAvoy pens a wonderful series of thrillers that push mysteries beyond what most writers would concoct and keeps the reader guessing until the end. Use of two forms of art in this piece make for added thrills in a book that tries to serve as a standalone, but also wonderfully complements McAvoy’s past trilogy. I cannot get enough of these books, as my binge reading has proven repeatedly.

The Dominic-Sinclair connection is back and both play wonderful protagonists again. They work together well, while complementing one another in numerous ways. McAvoy avoids more backstory for them, choosing instead to push these two deeper into their roles as sleuths who seek answers amongst the dust-laden documents inside the Secret Archives. There is surely a damsel in distress portion, but it’s not because Sinclair is weak or helpless. Rather, the ruthless group knows just how to find Dominic’s Achilles heel, even if he is not yet ready to admit it.

As with each of the three previous books, those who grace the pages of the book both complement and accentuate the protagonists. There are a number of great repeat characters whose supporting role cannot be overlooked. Alongside those names and faces series fans know well are the darker characters, those who wish nothing more than to flex their muscle and show that they will do whatever it takes to see secrets kept and lives sacrificed for the cause. McAvoy does a great job contrasting the good and evil, without the need for salacious killing or language.

As I read the book, I could not help but wonder if this could be the continuation of the past series. It flows so well and keeps the same pace I found in each of the Magdalene thrillers, but seeks to branch out a little. Father Dominic is back in the limelight and using his vocation to bring new adventures to light, even if they are filled with danger. McAvoy concocts a wonderful thriller with a powerful narrative push that is like few books I have seen before. Short chapters and clipped dialogue keep the reader pushing ahead, fuelled by a plot that is full of twists at every turn. I could not stop reading and found myself bingeing just to get through this book, more out of addiction to the story than anything else. Those who have yet to discover Gary McAvoy ought to begin with his Magdalene trilogy, though I suppose this could serve as a standalone (but why would you want to shortchange yourself?). I cannot wait to see what’s next, as I will be first in queue to get my hands on it.

Kudos, Mr. McAvoy, for another winner. You sure know how to spin a tale, with equal parts mystery and historical possibility.” — Matt Pechey, Reedsy Discovery


“When you read a book by Gary McAvoy you know exactly what you are going to get: high quality, incredibly well researched and detailed suspense, with a theme of ciphers and codes, and this book is no different.  Moving away from the theology somewhat now, The Vivaldi Cipher moves into the arena of fine art, the setting now from the Vatican to Venice, but with the same cast of characters – a clergyman, a reporter, a couple of Swiss Guard soldiers – that Gary has clearly come to know and love.  They are all endearing, and the author is adding layers to their overall narrative with every installment.  Perhaps a little too much of a slow burner to be called an exciting thriller, this book, like the others is gripping and hugely interesting, and the intrigue lies in the intelligent mystery of the cipher hidden in an unusual musical composition by former priest Antonio Vivaldi.

And “interesting” is certainly the most appropriate adjective for Gary’s work, and he clearly loves what he writes about, involving meticulous and conscientious research.  There’s a great appendix at the end of this book, in which Gary shares an insight into how he works as an author, and the diligent loyalty to his subject matter is clear; he is knowledgeable in everything he writes about, and crafts his stories with the authenticity of an authority in the clergy, the mafia, the Masters of fine art, classical music and special forces operatives.  There is something a touch darker about this book than the others, the characters more villainous and the threat more violent and closer to home; it is a very good and very worthy instalment to the series, adding a welcome change of direction, yet retaining its usual elements of high-level criminality involving the Catholic Church, this time spanning several centuries.

I like Gary and his writing a great deal.  It is well presented, entertaining and intriguing Sunday afternoon mystery, and his intellect shines through, treating his reading audience like grown-ups, which I always appreciate.” — Matt McAvoy, UK Reviewer (no relation to author)


“I want to express my gratitude to the author, Gary McAvoy for the exciting Vivaldi Cipher ARC. I have read with great pleasure the three previous books featuring Father Michael Dominic with friend and colleague, Hana Sinclair, and their quests and adventures regarding sacred Biblical relics. I was happy that they moved on to new and further investigations in this pulse-pounding new book.

This was an intense, thrilling, and fast-paced historical novel containing plenty of action and heightened danger. The author has once more seamlessly blended well-researched historical facts into a suspenseful, believable adventure with intriguing characters. References have been added at the end of the book explaining what is fact and which fictional parts were inserted to make this a gripping story. The city of Venice is the major location and adds to an immersive, vibrant sense of place.

Almost 300 years earlier, the eminent composer and priest, Vivaldi, was told by a Cardinal about his knowledge of the involvement of the Camorra,(part of the Italian Mafia) regarding their conspiracy in the forgery of valuable paintings by leading masters. Fearing that his knowledge could endanger his life, Vivaldi stored what he had learned in coded form in some musical notations. This Cardinal was murdered shortly after his admission. The art theft, forgery, and sale of valuable paintings throughout the centuries and down to the present day have been documented in what is known as the Coscia files. It appears that when priceless artwork is sent out to be repaired or restored, they are substituted for highly skilled forgeries, and either the fakes or originals are sold to very wealthy collectors. Records of the transactions involving the paintings, the buyers, and purchase prices are guarded in a safe by the present local Mafia don.

It is learned that many of the paintings stored in the Vatican are forgeries. Cardinal Petrini is greatly concerned. He has been the mentor, godfather, and more, to Father Michael Dominic who works in the Vatican’s Secret Archives. Michael and his friend, Hana are sent on a mission to Venice. Accompanying them are two highly trained Swiss Guards, Hana’s cousin Karl, and his partner Lukas. Hana enlists her former music teacher, an expert in musical cryptology, to translate Vivaldi’s code. An old friend of Michaels is now a priest at St. Marks and has heard in a confessional about art forgery and theft extending not only to the Vatican but possibly to the Uffizi Gallery in Florence. Once the Vivaldi code is translated, modern scientific analysis is used to examine the paintings. They need the Coscia files for evidence of listed forged paintings, the buyers of originals, their locations, and the prices paid.

Several people helping Michael’s group are murdered for their knowledge of the Camorra’s crimes, and the group is now in danger. At a lavish, masked Carnivale party attended by the prominent members of Venetian society, Hana encounters, Marco Picard, a former French commando, and Green Beret, who presently works security for her grandfather, a wealthy banker based in Geneva. Hana is annoyed that Marco has been sent by her grandfather to ensure her safety, but a romantic attraction develops between the two of them. This leaves Michael feeling unsettled and lonely, especially when taunted by Marco about his and Hana’s growing romance. Marco tends to be a secretive and violent lone wolf, his actions causing more wrath and vengeance from the Camorra. I didn’t care for the character but he was fearless, and when the others forgave him I felt I was bound to do so also.

Will they bring this crime syndicate to justice? Will they identify and recover the stolen artwork? Will Michael and Hana’s friendship endure, and can they share in further adventures?
Highly recommended to readers who enjoy a tense, action-packed historical novel containing crime, dangerous villains, cryptic clues, and endearing, undaunted protagonists. A stimulating, impeccably researched, well-plotted story.” —CAROLYN WALSH