Every Silver Gravity story centres women with agency.
Six Cryptic Codes. One Fearless Heroine. Infinite Danger.
If you love globe-trotting thrillers packed with ancient mysteries, high-stakes espionage, and a brilliant heroine who outsmarts everyone in the room, this is the bundle you have been waiting for.
Books 7 through 12 in the internationally bestselling Calla Cress Decrypter Thriller Series by Rose Sandy, collected in one unmissable ebook bundle. Calla Cress, British Museum curator, elite codebreaker, and covert operative, is back across six consecutive adventures, and the stakes keep rising.
Book 7: Atlantis of the Sands
A leather-bound book is stolen from Britain's most secure facility. Its pages appear blank but pulse with a force tied to a lost desert city swallowed by the sands three thousand years ago. When Calla's mentor vanishes with a desperate message, she must decode the rest before ancient sites begin to fall. Someone has already decoded enough of the city's secret to use it as a weapon. Racing against mercenaries, secret societies, and a biotech corporation, Calla must reach what the City of Pillars holds before they do. The secrets in the sand could heal the world, or ignite it.
Locations: Knossos, Berlin, GCHQ Cheltenham, Rub' al Khali desert
Book 8: Kingdom of Diamonds
A 17th-century shipwreck surfaces in the South African desert carrying carbonado diamonds that hum, whisper, and respond to neural technology in ways modern science cannot explain. A ruthless criminal mastermind known only as Savant wants them not for their value but for what they can do to the human mind. Calla is pulled back into the shadows, racing across continents as shifting loyalties threaten to undo her at every turn, and the man she has been forced to work alongside may be the most dangerous variable of all.
Locations: Kalahari Desert, Cape Town, Venice, Vatican City, Dubai
Book 9: The Falcon Syndrome
An ancient diary containing the genetic blueprint for immortality, created by a secret society of chemists centuries ahead of their time, falls into Calla's hands. A cryptic message from her colleague thrusts her into a high-stakes race against a corporate titan whose son's life hangs in the balance. Calla is not just chasing codes. She is hunting a predator while protecting knowledge that could transform or destroy humanity.
Locations: Zurich, Jerusalem, British Library London, Doha, Oxford, Tel Aviv
Book 10: The Queen of Sheba
Stone tablets containing fragments of the legendary Sheban Cypher surface, a mathematical system said to have given the Queen of Sheba unprecedented control over ancient trade routes. Calla discovers the cipher is not just historically significant. It is the mathematical key to controlling modern global shipping lanes worth trillions. As competing expeditions converge on the lost city of Sheba, Calla uncovers an earth-shattering secret: her parents once travelled these same deserts, possibly hiding a child with the same guardian abilities she is now manifesting.
Locations: London, ancient Yemen, the lost city of Sheba
Book 11: The Calculus Warning
Cryptic mathematical formulas begin appearing on government networks worldwide. Calla recognises a pattern: an 18th-century formula that perfectly predicts modern disasters. Rivers across Europe rise in perfect synchronicity, financial markets fluctuate with impossible precision, and weather systems align with mathematical certainty. Someone has unlocked The Calculus, a centuries-old manuscript that does not just predict catastrophes but forecasts exactly how humanity will respond. Calla must piece together the fragmented formula before a reclusive data scientist can sell the complete predictions to the highest bidder.
Locations: Paris, Zurich, Munich
Book 12: The Cobra Paradox
A lethal bioweapon codenamed Cobra is unleashed in Paris's black market. It is not just a virus. It is an adaptive entity that grows stronger with every attempt to neutralise it, bridging biology and technology and carrying an ancient consciousness with modern ambitions. Calla has 72 hours before a global activation sequence triggers worldwide catastrophe. As her unique abilities evolve, allowing her to sense the virus's adaptive patterns in real time, she uncovers a shocking connection between ancient Egyptian serpent cults and her own ancestral lineage. The key to stopping the pandemic is not destroying the Cobra. It is communicating with it, and only Calla can do that.
Locations: Cairo, Paris, ultramodern research facilities hidden in the desert
Fans of this series love:
- Race against time
- Ancient secrets with modern consequences
- Globe-trotting adventure across iconic locations
- Ciphers, puzzles and codebreaking
- Secret societies and shadowy enemies
- High-tech espionage meets historical conspiracy
- An unstoppable, brilliant heroine
- Betrayal, found family and reluctant allies
- World-at-stake stakes
Perfect for readers who love:
Dan Brown, Steve Berry, James Rollins, Scott Mariani, Ernest Dempsey, Clive Cussler, female-led action thrillers, cryptographic mystery, techno-thriller
Bundle and Save, get all six ebooks in one purchase and dive straight into the next chapter of Calla's world. No waiting. No gaps. Just pure, unputdownable thriller fiction.
Add to cart and start reading today.
For the physical book bundles, check the Bundles drop-down menu.
