Author R&R with M.B. Courtenay

Before turning to fiction, M.B. Courtenay lived and worked in Washington, D.C., Beijing, and New York City, and is fluent in Mandarin Chinese. He is the founder of Castlemartin, an independent publishing imprint. A lifelong student of history, philosophy, and the murky world of intelligence, Courtenay is a self-described "dabbler in espionage"—fascinated by the craft, its myths, and its moral gray zones. When not writing, he’s exploring the overlap between historical intrigue and modern tradecraft, reading everything from Will Durant to declassified Cold War files, and planning future installments in the Ethan Briar series.

The debut book in the series, A Spy Inside the Castle, is described as "John le Carré meets Black Mirror." It follows Ethan Briar, who was never a spy; he predicted risks—he didn’t take them. But when a cryptic message warns of a hidden war, he’s drawn into the shadows of Castlemartin Manor, a decaying stronghold hiding a conspiracy-driven regime.

At its heart lies ARCLIGHT, a quantum supercomputer built to predict the future. But ARCLIGHT’s inner circle doesn’t just forecast events—it controls them. Nations rise or fall by its design. Now, as ARCLIGHT turns its gaze on him, Ethan must navigate shifting loyalties, encrypted legacies, and the politics of modern intelligence to unmask FOXGLOVE, an operative whose betrayal could set the world on an irreversible path.

M.B. Courtenay stops by In Reference to Murder to take some Author R&R about researching and writing the book: 

 

Researching the Labyrinth: How I Built the World of A Spy Inside the Castle

When people ask me what it took to write A Spy Inside the Castle, I usually say: years of reading, pondering, and connecting the dots between worlds that don’t often meet. On the surface, the novel is a spy thriller—agents, secrets, and the familiar cloak-and-dagger. But beneath that layer, it’s about the systems that try to control us, the myths elites use to shape society, and the fragile agency of the individual. The research process felt less like building a library and more like navigating a labyrinth.

Walking Between Worlds

I’ve always been a nonfiction addict. My fascination with history began during the 2008 financial crisis, and it hasn’t stopped since. Back then, I’d go for long night runs outside under the stars, listening to audiobooks like Will Durant’s The Story of Philosophy or Professor Timothy Shutt’s Odyssey of the West lectures. Those voices that transported me through time became companions, pushing me deeper into the great philosophical traditions. That habit shaped a lifestyle of free thought, one that eventually demanded to be woven into fiction.

Living and working in China for more than seven years gave me a rare chance to inhabit an alternative world. As a fluent speaker and reader of Chinese, I wasn’t just passing through—I was immersed in daily life alongside friends and colleagues for whom that autocratic system was the only reality they had ever known. For me, though, it was both transformative and temporary: a new life I could enter and eventually step back out of. That tension between permanence and impermanence—between those bound to a system and those who move through it—shaped my mindset profoundly, and it is a theme I wove into my novel.

Inside the World of Intelligence

Later, living abroad and then working in Washington, D.C., I found myself "close enough" to the world of intelligence agencies to glimpse how it really works. I spoke with people inside the Agency, read the books they recommended, and studied the dry but fascinating mechanics of intelligence craft. What struck me most was not just the operations but the bureaucratic nature of secrecy itself. Intelligence, at its core, is about preserving American supremacy. That doesn’t always translate into directly protecting the American people—though I do believe most of those inside the system are sincere in their mission of protecting us citizens from foreign threats.

That tension became one of the engines of the novel. I wanted to explore the gap between what we see on the surface and what happens in the shadows.

From Headlines to Fiction

Much of A Spy Inside the Castle comes directly from current and near-future themes. I devour periodicals like Foreign Affairs and the Financial Times, jotting lines and fragments into OneNote until they balloon into sprawling pages. Those fragments become puzzle pieces, waiting for imagination to snap them into place.

The result is a story where fiction and reality blur. The far-right German political party Steigen für Deutschland (SfD) is clearly modeled on the real-world AfD. Project NIGHTSHADE, with its quantum supercomputer for predictive analytics, is a fictional outgrowth of the post-9/11 Total Information Awareness program—an initiative shut down in 2003 after public backlash against its intrusion on civil liberties. The more I researched, the more I saw how plausible these fictional "what ifs" could become.

History, Myth, and the Labyrinth

As a student of history, I take to heart the old adage that all philosophy is a footnote to Plato. Many of our deepest questions have already been asked. That’s why I gravitate toward classical myths like Theseus and the Minotaur. They’re timeless frameworks we can still use to understand power, choice, and sacrifice.

In the world of A Spy Inside the Castle, the labyrinth isn’t only Castlemartin—the remote Scottish estate where much of the novel unfolds. It’s also the system itself: the secret societies and shadow networks that, since the Treaty of Westphalia in 1648, have worked to control nation-states from behind the curtain in order to maintain balance of power. It’s a labyrinth with no outside. Someone must always step into the role of the Minotaur, or else a vacuum opens. The novel asks: what do we do with a labyrinth that cannot be escaped? Whether we like it or not, someone has to manage the labyrinth. Someone has to take and accept the responsibility of leadership and power.

Pulling It All Together

For me, research is not about piling up facts—it’s about finding resonance. I wanted to write a thriller where the AI, the geopolitics, and the mythology don’t just decorate the story; they give it depth. The plausibility comes from the way real history, current events, and myth converge. That’s where I find my creative spark: at the crossroads of nonfiction detail and imaginative possibility. 

You can learn more about M. B. Courtenay via his website and follow him on Instagram. A Spy Inside the Castle is now available via all major booksellers.