Mick Herron, author of the phenomenally successful Slough House espionage novels, has been hailed as the best spy novelist of his generation. His bestselling, award-winning series following MI5 agents who have fallen from grace expanded its fan base recently with “Slow Horses,” the 2022 Apple TV+ adaptation starring Academy and BAFTA award-winners Gary Oldman and Kristin Scott Thomas. Now, Herron will delight fans both old and new with his prequel to the series, The Secret Hours. Set in the post-Cold War era, Herron’s pithy and tense latest slowly reveals the cover-up of a classified op gone wrong, casting three decades of U.K. intelligence history in a radical new light. 

How will the experience of reading The Secret Hours differ for new readers versus established fans of the series?
It’s impossible to quantify the experience of new readers, but I hope they’ll find The Secret Hours a story that’s complete in itself, and not feel excluded from any larger framework. Regular readers will notice familiar elements, though; for example, the Regent’s Park setup, which—as in the Slough House novels—is the center of the U.K. intelligence service. And there are a few Easter eggs along the way . . .

Does The Secret Hours have its own distinctive tone?
I hope so. Though set much in the same world as the Slough House novels, it features different characters and required a different narrative voice at times. It opens, for example, with a lengthy chase sequence, which is a bit more frantic than my usual openings. I wanted to drag the reader along—make them feel they’d been hijacked, almost.

What’s your typical practice in regard to research and verisimilitude for the series, and did you have to do anything different when taking on the Cold War era?
I’m not a great fan of research, for the most part, and only resort to it when absolutely necessary. When writing the Slough House books, I’m usually writing about London in the present day, so I can achieve a certain amount of verisimilitude simply through observation. But part of The Secret Hours is set in post-reunification Berlin—the years immediately after the Cold War ended—and this required a little more work. I focused on finding out what the city would have looked and smelled like. Who would have been most visible on its streets. What people did for entertainment. That sort of thing.

You’ve been hailed as the John le Carré of your generation. How did you feel when you first heard that comparison, and did it affect how you wrote?
Any comparison to le Carré is both hugely flattering and somewhat misapplied. Le Carré was unique—there’ll never be another. His work defined the Cold War era. My work will never match up to that. If the comparison has brought new readers to my books, it’s done me a favor, but I’ve never tried to live up to it in the sense of trying to write more like him. That would be doomed to failure.

What first piqued your interest in the world of espionage? Were you an avid spy novel fan as a young reader?
I read le Carré, of course, and also Deighton, and also—in many ways, more importantly—about a million other thrillers I no longer remember, of hugely varying quality. Quantity matters more at that stage. Reading everything you can get your hands on helps you develop your own intuition about storytelling: what works, what doesn’t, what’s new, what’s been done a hundred times. The spy novel, though, wasn’t a particular interest; just one among many. I liked most stories—I was a total addict. Still am.

Unlike the high-flying protagonists of many other espionage series, the inhabitants of Slough House are all outcasts in some way. What made you want to center spooks in professional purgatory?
It’s largely because I wanted to write about failure, which I find intrinsically more interesting than success. More relatable, too. Few of us know what it’s like to be a hero, or, say, freefall from a helicopter. But we’ve all had squabbles in the workplace.

Having studied English literature at Oxford, you have a deep and varied literary background. Who do you think of as important authorial influences? Do they cross genre boundaries?
There are dozens, hundreds, of writers I admire, but it’s not easy to say who I’m influenced by. They’re not necessarily overlapping categories anyway: There’s no living thriller writer I admire more than Martin Cruz Smith, but I don’t try to write like him and have never noticed myself doing so. A writer’s voice generally develops piecemeal, and by the time it’s formed, there’s no telling where its origins lie. 

Thinking about it, I’ve probably been consciously influenced more by poets than by thriller writers. Not so much individual writers (though a keen-eyed reader might spot borrowed images, or even whole lines, from various poets on pages I’ve written) as the control that poetry requires: the weighing of individual words, the balancing of sentences with each other. All the things that go towards making writing seem natural. Genre writing is often dismissed as sub-literary, but only by people who don’t know what they’re talking about.

The Slough House series was recently translated to the screen via the spectacular “Slow Horses” TV show. What was your role in that development process and how did the team for “Slow Horses” come together?
Thank you for that “spectacular”! I have a consultant’s role on the show and spend time in the writers room, taking part in the discussions around adapting the plots and storylines so that they meet the demands of the new medium. The team itself was put together by the people, now my friends, who first approached me about the show: Jamie Laurenson, Hakan Kousetta and Gail Mutrux. I’m in their debt.

Were there ground rules or nonnegotiable elements that you had in mind or stipulated in the deal for “Slow Horses”?
I’m pretty sure they’re not allowed to kill or maim any of the characters without my express permission.

What are you reading now?
Like many people, I did a lot of re-reading—comfort reading—during the pandemic, and for me, the habit has endured. One of my go-to writers is Robert Goddard, many of whose works I’ve re-devoured these last few years. He’s a fabulous storyteller, consistently surprising without ever resorting to cheap trickery. His latest is out soon, and I’m looking forward to it, but I’m currently re-reading Out of the Sun.

Photo of Mick Herron by Jo Howard.