Out now, a two-book series

The Key Series

The Key Series follows ex-special forces operator James O'Neill and senior MI5 officer Sarah Sterling as they deal with the fallout from a stolen GCHQ simulation drive and the rise of The Grey Wind, a model built to detect hostile activity across the UK's power, data, and financial systems.

These grounded British espionage thrillers focus on operators, analysts, and private contractors fighting quiet wars inside networks, ports, and control rooms where a small "glitch" can carry national-level consequences.

If you read SAS and MI5 thrillers grounded in real cyber warfare and British intelligence, this series was written for you.

Available on Kindle · all major eBook platforms
Book cover of The Lost Key by James O'Neill — a British espionage thriller
Read on your Kindle, tablet, or phone.

Author

Personnel File  ·  Restricted
Designation James O'Neill
Service UK Special Forces
Years Active 20+ Years
Theatre Europe · Middle East · US
Current Location
Active Operations
EYES
ONLY

James O'Neill spent over twenty years in UK Special Forces and private security consulting — the kind of career that exists in operational reports and nowhere else.

He didn't set out to write fiction. He set out to solve problems: quietly, without attribution, in places that don't feature in press briefings. Over two decades, that work took him across Europe and beyond, into environments where the difference between an ally and a threat was rarely obvious, and where the ability to read patterns — not react to events — was the only reliable edge.

That discipline shapes everything he writes. His protagonist, James O'Neill, operates by a single rule: nothing is real until it happens three times, and you must witness each one. It isn't a dramatic device. It's the kind of logic that keeps people alive in environments where the obvious answer is usually planted.

The tradecraft in these novels isn't invented or researched from the outside. It's the residue of a long career — the field logic, the institutional compromises, the texture of work done far from cameras and official statements. The names have changed. The patterns haven't.

His debut thriller, The Lost Key, is out now. His second novel, The Grey Wind, is also out. Both are written from the same place his career was built: close to the detail, and a long way from the noise.

Books

Book cover of The Lost Key by James O'Neill — British espionage thriller
A James O'Neill Thriller  ·  Out Now
The Lost Key
The quietest operations leave the deepest damage.

When a classified GCHQ drive disappears, there's no explosion. No headline. Just a file called Lost Key moving through the wrong hands — and a former SAS operator who knows that the quietest problems are always the most dangerous.

James O'Neill didn't go looking for this. But his name is showing up in the wrong reports.

An old MI5 contact. A hunt from Belfast to Warsaw. A drive that can quietly unlock the West's most secure infrastructure — and hostile states who are starting to realise what they're holding.

Every step is watched. Every contact is a question. Nothing is real until it happens three times.

Kindle · all major eBook platforms · paperback
Amazon UK Amazon US
Book cover of The Grey Wind by James O'Neill — British cyber thriller
A James O'Neill Thriller  ·  Out Now
The Grey Wind
No sirens. No headlines. Just damage.

A year after Lost Key, James O'Neill wants a quiet life. MI5 officer Sarah Sterling wants to close the file. Neither gets what they want.

Someone is running a quiet campaign against Western infrastructure — ports, grids, financial systems — applying pressure without fingerprints, without triggering open conflict. When the attacks start mirroring a classified Red Team exercise, the question stops being who's behind it.

The question is how far their own side helped build it.

Kindle · all major eBook platforms
Amazon UK Amazon US

Briefing List

News & Updates

  • Out Now The Lost Key is available on Amazon Kindle, all major eBook platforms, and paperback. If you've read it, a review on Amazon or Goodreads makes a real difference — thank you.
  • Out Now The Grey Wind, the second James O'Neill thriller, is also out now on Kindle and all major eBook platforms. Join the Briefing List →
  • Follow Along Behind-the-scenes updates and occasional special offers on Instagram: @jamesoneillthrillers

Contact

General & reader email info@jamesoneillthrillers.com
Film / TV / audio rights For rights, translation or media enquiries, please introduce yourself via the email above with the subject line: RIGHTS ENQUIRY — JAMES O'NEILL.