Silver Gravity Books
The Decrypter: Secret of The Lost Manuscript, Book 1 - Rose Sandy
The Decrypter: Secret of The Lost Manuscript, Book 1 - Rose Sandy
Thriller & suspense, Technology, Action & adventure, History, Crime & mystery, Suspense, and Romance
Book Number in Series
Book Number in Series
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When your life was built on a lie, discovering your true identity can be deadly.
When Calla Cress joins an elite taskforce to investigate the mysterious Hadrius Manuscript, she uncovers a conspiracy that connects her troubled past to a global threat hidden in plain sight.
Calla Cress has been searching for her missing parents for her entire life. She thought the mystery was long buried, but when a two-thousand-year-old manuscript with an unbreakable code lands in her hands, she is suddenly thrust into a desperate race against time.
As the British Museum curator deciphers the cryptic message, she becomes the target of a secret government agency enemy determined to keep the truth hidden at all costs. When the manuscript vanishes in Berlin, Calla realizes that the key to her family's disappearance may be encoded in the ancient text.
With no time to lose, Calla, NSA security advisor Nash Shields, and tech entrepreneur Jack Kleve set off on a globe-trotting mission to decode the riddle and uncover a shocking technological breakthrough. But as she battles against skilled assassins and unravels the layers of deceit, she realizes that nothing in the modern or ancient world is as it seems.
As the clock ticks down, Calla must risk everything to solve the mystery of her missing parents and prevent a dangerous new world from being unleashed. This is a race against time that she cannot afford to lose.
Experience the rush of danger and the thrill of the chase in this thriller, perfect for fans of Ernest Dempsey, Jason Bourne, Steve Berry, Scott Mariani, and Clive Cussler.
Reader Praise
"Calla's search for her identity had me completely invested, I was rooting for her from page one. The chemistry between her and Nash absolutely sizzled, and I'm already dying for book two!"
"What starts as a cryptography puzzle evolves into something much deeper about identity and belonging. Sandy weaves historical elements with modern technology in ways that feel both authentic and thrilling."
ABOUT THE SERIES
ABOUT THE SERIES
Calla Cress is no ordinary museum curator. By day, she manages ancient manuscripts, Byzantine relics, and rare artifacts at the British Museum. But in the shadows, she’s a top operative, for a covert multi-government spy agency. With unparalleled skills in cryptography, ancient languages, and digital intelligence, Calla is known asThe Decrypter,the one they call when the stakes are global and the clues are buried deep in history.
The Calla Cress Technothriller Series
Introduction: The Curator and the Code
Calla Cress is a brilliant curator at the British Museum, a woman whose unparalleled command of history and ancient languages has made her a luminary in the academic world. Her quiet life shatters when she’s recruited to decipher a cryptic, long-lost manuscript written in an apparently unbreakable code. The secrets locked inside are no mere curiosities: they map the location of resources that could make crude oil look obsolete. Thrust from scholarly halls into the shadows of global espionage, Calla learns that priceless artefacts can be triggers for future wars—and her first mission is only the beginning.
The Scope of the Conspiracy: A Global Race Against Time
What starts with a single manuscript escalates into a worldwide battle against a cascade of interlinked threats. The Calla Cress series blends historical mystery, high-stakes international espionage, and cutting-edge technothriller energy. From London and Paris to the deserts of Morocco and the jungles of the Congo, Calla and her allies piece together clues centuries in the making. Hunted at every turn by relentless foes—wielding carbonado diamonds and moving like computer-augmented phantoms—they bend physics and technology to their will. With each book, the stakes rise and the pace accelerates, as Calla uncovers a conspiracy vast enough to bring the world to its knees.
A Promise to the Reader: Unforgettable Adventure
Expect an action-packed ride from first page to last—breathless momentum with brains and heart. Each instalment delivers intricate mystery, breathtaking suspense, and relentless thrills. If you love globe-trotting puzzles, fierce heroines, and technothrillers that never let up, the Calla Cress series belongs on your shelf.
Main Characters
Calla Cress—the series protagonist—is a British Museum curator and ISTF agent on a personal crusade to uncover her origins and the truth behind her genetically enhanced abilities. Facing cryptic codes and dangerous foes, her journey pushes her cyber-espionage skills to the limit. Across the series she evolves into a formidable operative, determined to reconcile the mysteries of her past with her present while battling adversaries who weaponise her own secrets against her.
Jack Kleve is the quintessential ally—a visionary tech entrepreneur and ISTF operative who lends his skills to Calla Cress and Nash Shields. While navigating corporate rivalry and the murky ethics of rapid technological advancement, his arc bends towards recognising the greater good over profit. Jack’s devotion to Calla adds a personal dimension to his conflicts, intertwining the professional with the emotional. His shift from profit-driven inventor to socially conscious partner marks a pivotal transformation in the series.
Nash Shields, an NSA and ISTF agent, is the steadfast protector and love interest, driven by a profound sense of duty. He confronts formidable enemies and complex political networks while safeguarding vital technologies alongside Calla. His journey forces him to question the ethics of his mission, balancing loyalty to his agencies with a deepening moral awareness. Torn between professional duty and personal feelings, Nash walks a precarious line between love and allegiance.
SERIES READING ORDER
SERIES READING ORDER
The Calla Cress Decrypter Thriller Series In Order
- Book 1: Secret of the Lost Manuscript
- Book 2: The Mind Hacker
- Book 3: Digital Eyes Only
- Book 4: The Storm’s Eye
- Book 5: The Pythagoras Clause
- Book 6: The Beale Ciphers
- Book 7: Atlantis of the Sands
- Book 8: Kingdom of Diamonds
- Book 9: The Falcom Syndrome
- Book 10: The Queen of Sheba
- Book 11: The Calculus Warning
- Book 12: The Cobra Paradox
- Book 13: Room of Martyrs
- Book 14: Eiger Mosaic
- Book 15: Enemy of Wolves
- Book 16: The Pharaoh's Mask
- Book 17: The Eternity Hypothesis
- Book 18: The Sculptor's Code
- Book 19: The Solomon Agenda
- Book 20: The Pheonix Cipher
- Book 21: The Cairo Key
- Book 22: Red Fox Agenda
- Book 23: Phaistos Disc
- Book 24: Scorpion Gold
READ A SAMPLE
READ A SAMPLE
Meet the Author
Meet the Author
Rose Sandy writes adventure thrillers that blend espionage, technology, and history into fast-paced adventures. Her stories dive into the world of covert intelligence, scientific breakthroughs, and global conspiracies, perfect for readers who love suspense with a twist of "what if?" Whether you're on a morning commute or relaxing on a Sunday, her books promise to entertain, surprise, and transport you to hidden corners of the world.
A true globetrotter and lifelong communicator, Rose draws inspiration from historical archives, cutting-edge tech, and conversations with intelligence insiders. When she's not researching in the British Library or exploring Churchill’s War Rooms, she’s crafting thrillers that weave intrigue, action, and a hint of romance. Discover more here or join her newsletter at subscribepage.io/Wuqko4.
Tropes You'll Love
Tropes You'll Love
heroine with great abilities, cryptographer protagonist, ancient manuscript mystery, international espionage thriller, enemies to lovers tension, found family/chosen identity, high-stakes conspiracy, academic thriller setting, technology meets history, action-packed female lead, secret government agency, slow burn romantic tension, female spy protagonist, Oxford University mystery, NSA operative romance, decoding ancient secrets, woman with extraordinary powers, intelligence agency recruitment, historical conspiracy thriller, European action adventure
Audio Book Sample
Audio Book Sample
Other Book Details
Other Book Details
- Pages 494
- ISBN TBC
- Paperback Dimensions :5 x 0.51 x 8 inches
- Language English
- Categories: Espionage Thrillers, Technothrillers, Action & Adventure Fiction, Romantic Suspense, Paranormal Suspense
- Series: The Calla Cress Decrypter Thriller Series, Book 2
FAQs
FAQs

This is an author I was unaware of but the subject matter was intriguing and it was free to download so I thought why not? I read the first 2 books back to back and really enjoyed. Anyone with an interest in ancient codes and archaeology will love these, Calla Cress is a bad ass with 2 best friends who, as underdogs, you find yourself rooting for. I look forward to reading the rest of the series.
This is a fast action book with one twist and turn after an other. Once you start reading you can't put it down.
As this is the first in the series I'm looking forward to continuing with the rest.
The Decrypter: Secret of The Lost Manuscript - Book 1
Loved this book I couldn't put it down. I recommend it you will enjoy it
Superbly good reading fast action keeping you enthralled through out
Would recommend
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