Silver Gravity Books
The Decrypter and the Kingdom of Diamonds - Calla Cress Decrypter Thriller Series, Book 8 Female-led action-adventure techno-thriller
The Decrypter and the Kingdom of Diamonds - Calla Cress Decrypter Thriller Series, Book 8 Female-led action-adventure techno-thriller
Thriller & suspense, Suspense, Sci-fi, Technology, Action & adventure, Crime & mystery, History, and Romance
Every Silver Gravity story centres women with agency.
FREE instant Ebook version with every hardback, paperback or audio sale!
FREE instant Ebook version with every hardback, paperback or audio sale!
EBOOKS ARE DELIVERED INSTANTLY. YOUR DOWNLOAD LINK ARRIVES BY EMAIL RIGHT AFTER CHECKOUT. PAPERBACKS/HARDBACKS ARE PRINTED TO ORDER AND TYPICALLY SHIP IN 3–7 DAYS.
EBOOKS ARE DELIVERED INSTANTLY. YOUR DOWNLOAD LINK ARRIVES BY EMAIL RIGHT AFTER CHECKOUT. PAPERBACKS/HARDBACKS ARE PRINTED TO ORDER AND TYPICALLY SHIP IN 3–7 DAYS.
Couldn't load pickup availability
A brilliant curator. A criminal mastermind. A lost ship whose cargo could shape the future of humanity, or destroy it.
When a 17th-century ship loaded with impossible diamonds resurfaces deep in the South African desert, elite codebreaker Calla Cress is drawn back into a world of shadows, secrets, and silent warfare. Decoding the ship’s true location means confronting a past she thought she’d buried, and a power no one should control.
The diamonds aren’t ordinary gems. Known as carbonado, they hum, whisper, and react to neural technology in ways that defy modern science. As whispers of their capabilities spread, a ruthless criminal mastermind known only as Savant launches a global hunt through her shadow organisation, Paragon — determined to weaponise the stones and accelerate human evolution itself.
As Calla races from the Kalahari Desert to Cape Town, from Venice’s masked ballrooms to Vatican City and Dubai’s black-market auctions, shifting loyalties threaten to undo her at every turn. Forced to work alongside former agency boss-turned-fugitive Mason Laskfell, Calla must decide who she can trust — and whether some secrets are too dangerous to decode.
Blending ancient legends, cutting-edge biotech, and high-stakes espionage, The Decrypter and the Kingdom of Diamonds is a pulse-pounding techno-thriller where every revelation carries a cost — and some truths are worth killing for.
Reader Praise
“Fast-paced and cinematic, Calla Cress is back in her most personal and powerful mission yet.”
“Diamonds that whisper, neural tech, and ancient secrets, this one has it all!”
“A must-read for fans of action, mystery, and smart thrillers.”
“Rose Sandy’s best work to date equal parts exciting and thought-provoking.”
Locations & Interesting Places in the Book
Kalahari Desert, Botswana – Hidden caves filled with carbonado diamonds that hum and whisper. The desert becomes the final battlefield for control over humanity’s future.
Cape Town, South Africa – A sleek biotech conference where NS-217 is revealed to the world—and its dangers become terrifyingly clear.
Venice, Italy – A masquerade ball at Aman Canal Grande sets the stage for revelations and betrayals in a city of masks and secrets.
London, UK – From the British Museum to Blackhorse Archives, Calla’s home turf becomes the hub of encoded clues, family secrets, and decisions that shape her destiny.
Vatican City, Rome – Perry Cress executes a daring heist that kicks off the trail toward the Kingdom.
Dubai – A black-market auction where a diamond fragment changes everything.
Khoisan Villages, Botswana – Ancient oral legends, cave paintings and spiritual warnings guard the Kingdom’s truth.
Listen to the series here:
About the Calla Cress Decrypter Series
About the Calla Cress Decrypter Series
The Calla Cress Decrypter Series is a female-led action-adventure techno-thriller series that blends global espionage, cryptography, and high-stakes discovery.
Often compared to a female James Bond crossed with Indiana Jones, the series follows Calla Cress, a brilliant cryptographer and museum curator whose expertise in ancient manuscripts and hidden systems draws her into international conspiracies. As intelligence agencies, criminal networks, and secret organisations collide, Calla is forced to navigate a world where knowledge is power — and decoding the truth can destabilise nations.
Each book stands alone while contributing to a larger arc of global intrigue, making the series perfect for readers who enjoy smart, fast-paced thrillers led by a woman who survives on intellect, courage, and moral clarity rather than brute force alone.
What Kind of Thriller Is This?
What Kind of Thriller Is This?
This book is best described as a female-led action-adventure techno-thriller.
It combines:
- Technothriller elements (cryptography, data, hidden systems, modern intelligence warfare)
- Espionage and conspiracy involving governments and shadow organisations
- Action-adventure storytelling across global locations
- A smart female protagonist whose intelligence drives the plot
If you enjoy thrillers where ideas are as dangerous as weapons — and where discovery triggers global consequences — this series is designed for you.
If You Love James Bond or Indiana Jones…
If You Love James Bond or Indiana Jones…
Readers often compare this series to James Bond and Indiana Jones, but with a modern, female-led twist.
- Like James Bond, the story features global stakes, intelligence agencies, and dangerous conspiracies.
- Like Indiana Jones, it revolves around ancient knowledge, hidden artefacts, and discoveries that reshape history.
What sets Calla Cress apart is that intelligence is the primary weapon. Codes replace gadgets. Pattern recognition replaces brute force. And the heroine’s strength lies in insight, scepticism, and resolve.
Story Tropes & Reader Appeal
Story Tropes & Reader Appeal
This book is ideal if you love:
- Female-led techno-thrillers
- High-stakes global conspiracies
- Ancient mysteries paired with futuristic science
- Action, intrigue, and moral dilemmas
- Smart heroines navigating worlds of deception
You’ll especially love this one if you’re fascinated by hidden ships, rogue biotech, criminal empires, and thrillers where evolution itself is the battlefield.
Is This Book for You?
Is This Book for You?
This book is ideal if you love:
- Female-led techno-thrillers
- High-stakes global conspiracies
- Ancient mysteries paired with futuristic science
- Action, intrigue, and moral dilemmas
- Smart heroines navigating worlds of deception
You’ll especially love this one if you’re fascinated by hidden ships, rogue biotech, criminal empires, and thrillers where evolution itself is the battlefield.
Do I Need to Read the Series in Order?
Do I Need to Read the Series in Order?
Each Calla Cress novel is written to stand alone, with its own central mystery and resolution.
However, reading the series in order allows you to follow Calla’s evolving relationships, growing influence, and the wider conspiracy arc that unfolds across the books. New readers can start here, while returning readers will uncover deeper connections.
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
About Rose Sandy
About Rose Sandy
Rose Sandy is an independent author and publisher known for writing female-led action-adventure and techno-thriller fiction.
She is the creator of the Calla Cress Decrypter Series, a globe-spanning techno-thriller series often compared to a female James Bond crossed with Indiana Jones. Her work blends cryptography, global conspiracy, and high-stakes discovery, with a focus on intelligent heroines who survive through insight, courage, and moral clarity.
Rose Sandy’s stories are characterised by fast-paced plots, international settings, and the collision of history, technology, and power. Her fiction is written for readers who enjoy smart thrillers with real-world stakes and strong female protagonists at the centre of the action.
Read or Hear a Sample
Read or Hear a Sample
Genres & Themes
Genres & Themes
Genres & Themes
Genres:
- Action-Adventure Thriller
- Techno-Thriller
- Espionage & Intelligence Thriller
Themes:
- Knowledge as power
- Truth versus control
- Women in high-stakes intelligence spaces
- History colliding with modern technology
- Moral courage under global pressure
The Kingdom of Diamonds took me on an emotional rollercoaster! Calla's struggles with identity and belonging really resonated with me - her question of "what is normal?" felt so real despite the fantastical setting. The desert expedition was pure edge-of-your-seat thriller material. I loved how the author wove together family secrets, advanced technology, and ancient mysteries. The betrayals genuinely shocked me, particularly the reveals about Allegra and Mason. The ending left me desperate for the sequel!
As someone fascinated by both genetic engineering and archaeological mysteries, this book hit all the right notes. The scientific explanation for the Embankers' abilities through advanced biotechnology was convincing, and the idea of diamond rocks enhancing these genetic gifts was creative. The blend of modern conspiracy elements with ancient secrets worked surprisingly well. Calla's code-breaking abilities and the various cipher challenges throughout added an intellectual puzzle element I really enjoyed. The multiverse theory explanations were well-researched.
This book absolutely delivered on every front! Calla Cress is such a compelling protagonist - her journey from uncertainty to fierce determination kept me glued to the pages. The Kalahari Desert sequences were breathtaking, and the team dynamic between Calla, Nash, and Jack felt so authentic. The science behind the carbonado rocks and the multiverse elements added a fascinating layer without being overwhelming. The trust issues and betrayal themes hit hard, especially with Calla's complex relationships. Can't wait for the next installment!
What sets this book apart is the incredible world-building around the Embankers and their hidden society. The concept that humanity reached its technological peak millennia ago and these enhanced beings live among us is fascinating. The carbonado rocks as power amplifiers, the secret government operations, the Cress family's special genetics - everything interconnects beautifully. Calla's supernatural abilities (gravity manipulation, enhanced strength, x-ray vision) were explained through solid scientific theory rather than hand-waving. A must-read for world-building enthusiasts.
The Kingdom of Diamonds delivers a compelling adventure story with interesting sci-fi elements. Calla is a strong protagonist, and her supernatural abilities are well-integrated into the plot. The desert expedition was the highlight - tense, atmospheric, and beautifully written. The antagonist Savant provides good motivation for the treasure hunt. However, some middle sections felt a bit rushed, and I would have liked more development of the supporting characters beyond Nash and Jack. The trust and betrayal themes were powerful but could have been explored deeper. Still a very enjoyable read overall.
Learn more about all our series
Where imagination knows no bounds and adventure awaits at every turn.
