Sebastian Reth

A student of the crack in the door and the whisper in the hallway, obsessed with the points where morality meets desperation. Currently residing in the shadows of New Zealand’s financial sector, watching the numbers—and the people who move them.

Available Now (Fiction)

The Soul Beneficiary
A Forged Deed. A Mercantile Hitman. A Town Built on Buried Secrets.

The Soul Beneficiary

Julian Miller is an expert at finding the cracks in other people’s balance sheets. But when his Auckland investment firm collapses into a fraudulent mess, he is forced to flee to his only remaining asset: an isolated bach on the cliffs of Onemana.

In a town where the Pacific is a graveyard, Julian must pivot from auditor to predator. There is no such thing as walking away clean.

Order Now
Read on Kindle Unlimited
The Thames Protocol
Synthetic Mercy. Cold Logic. Zero Trace.

The Thames Protocol

In the quiet wards of Thames Hospital, a new era of patient care has arrived. The "Protocol" AI is sleek, silent, and supposedly infallible. But when a patient is found dead in a locked room with zero human trace, the system's cold logic points to a terrifying conclusion.

Order Now
Read on Kindle Unlimited

Available Now (Non-Fiction)

Between the Lemons
Happiness isn't a destination. It's a muscle.

Between the Lemons

Most of us are running on a treadmill of our own making. The career is stable, the family is healthy, but underneath, there is a low-grade hum of dissatisfaction. Between the Lemons is a field guide for the restless and the burned-out who suspect that "having it all" shouldn't feel this exhausting.

Drawing on evolutionary psychology, stoic philosophy, and hard-won experience, this practical toolkit will help you Hack Your Survival Brain, Stop treating emails like saber-toothed tigers, Pass the Saturday Morning Test, Overcome "Leisure Guilt", Learn the art of doing nothing, Debunk the Soulmate Myth, and Face the Man on the Roadside.

Order Now
Read on Kindle Unlimited

Coming Soon

Pre-Order Now
Broken Hills
Lost in the Bush. Hunted by the Elite. The Broken have eyes.

Broken Hills

In the scarred wilderness of the Coromandel’s Broken Hills, a weekend tramp turns into a nightmare. When a hiker is violently snatched away in the mist, the survivors discover they have stumbled upon the ultimate gated community: a secret bunker complex for billionaires hidden deep within ancient gold mine shafts.

Trapped in the dense bush with no signal and ruthless private security forces closing in, the hikers must stop being victims and start acting like prey if they want to survive the night.

Pre-Order Today

Arriving Early 2026

The Author

Sebastian Reth

Sebastian Reth

Sebastian Reth is a writer of dark, atmospheric thrillers that explore the terrifying fragility of modern life. When he isn't plotting the downfall of fictitious characters, he can be found exploring the rugged backroads of the Coromandel on a motorcycle or experimenting with gin distillation in his garage. He lives in New Zealand with his wife, and is a father to three sons.

Unlock the Auditor's Files

Sign up for the Sebastian Reth newsletter to receive exclusive prequels, dark insights, and updates on new releases.