Mick Herron discusses his latest thriller and a career writing detective and espionage stories

The latest novel from Mick Herron manages to be two things at once: both a gripping standalone espionage thriller for readers who have never read anything else by the author, but also a must-read for fans of his bestselling Slough House series as, delving back into the past, it reveals a hidden history.

The Secret Hours is set in present-day London where the Monochrome inquiry is under way. Set up two years earlier to investigate wrongdoing by the British intelligence service, it has hit the buffers very slowly, one grindingly dull and irrelevant witness at a time. Civil servants Griselda Fleet, a tired but diligent Black woman in her fifties, and Malcolm Kyle, a Cambridge graduate who, in his own mind, was once the bright hope of the Civil Service but is now sensing otherwise, marshal the lacklustre panel: two backbenchers chiefly concerned with claiming expenses, a Labour MP “regarded by all who had never worked with her as a diligent operator”, a glamorous crime-writer with a massive Twitter following and an entrepreneur recently awarded a multi-million pound contract by the government.

I’m only ever a page and half, as far as the plot goes, ahead of the reader

Herron’s terrific wit is to the fore here, as the civil servants fret privately that the inquiry is sounding the death knell of their respective careers. Over Zoom from his home in Oxford, where he has lived since leaving his home city of Newcastle, to study at the university, Herron observes: “There’s something about frustration and failure and career despair that really appeals to me when I’m writing… it just seems to be where my imagination takes me."

“Fundamentally, if I could write a book in which all the characters were sitting in the same room, squabbling, that is probably what I would do. The demands of the thriller require a character to go out of the room and get involved in car chases or whatever, but I like that kind of conflict—where people who just don’t get on are forced to co-operate.”

Past informs the present

When a security file labelled “OTIS” appears under mysterious circumstances, a new and credible witness prepares to give her testimony and the stagnating inquiry jolts into action. This account moves the story back to post-unification Berlin in the early 1990s, aka The Spooks’ Zoo, where spies, fixers and innocents cross paths in a gripping tale of betrayal and revenge. This distant past is now bleeding through to the present, with a long-retired spy forced to go on the run in sleepy Devon, pursued by unknown (and suspiciously inept) intruders, and the head of the intelligence services, known only as First Desk, taking a close interest.

It is superbly, breathtakingly, well-plotted but Herron says he doesn’t do too much in advance. He keeps “a broad shape” in mind but there is no wall of intricately connected Post-It notes: “I do it on the hoof as it were. I’m only ever a page and half, as far as the plot goes, ahead of the reader.” His depiction of Berlin, a few years after the fall of the Berlin Wall, is also masterly. He claims to be “quite research-averse”, one reason why he is drawn to the contemporary rather than this historical, but he wanted to capture the feel of the city back then, “the anarchy, the difficulties of reunification, the social chaos of those years”.

It is a novel about today’s world, but also one that looks at the roots of how my characters got where they are, about how the world that I’ve been writing about for the past 15 years or so

Herron describes The Secret Hours in deliberately opaque terms, keen only to hint at the novel’s connection to the Slough House series. “It is a novel about today’s world, but also one that looks at the roots of how my characters got where they are, about how the world that I’ve been writing about for the past 15 years or so—where some of those roots lie.”

“Herron is at the summit of a new golden age of spy fiction”, according to the Sunday Times, but his journey to the top has been a gradual ascent. His first novel, Down Cemetery Road, was published in 2003 by Constable & Robinson after “doing the rounds of most publishing houses”, he says now. The character of Zoe Boehm “only cropped up towards the end”, but when he came to write his second, he decided to make the Oxford private investigator the central character, and the Zoe Boehm series eventually ran to four books, published by Constable & Robinson.

He made the move from detective stories to espionage with Slow Horses which he began writing in 2008, the year of the financial crash. It was published in 2010, but sales were slow, and so Constable declined to publish the second in the series. “I think it wasn’t the right time for it really. The main themes—loss and regret and grief—they are, I hope, very funny, but they are quite bleak. If you took the humour out it would probably be the spy novel meets Samuel Beckett or something, all these people would be sitting around mourning their lost careers! There’s political satire in there as well, and I think the appetite for that really came about post-Brexit, so the books came into their own then. Nobody was interested much beforehand.”

His US publisher kept the faith, and Dead Lions was published by Soho Press, but it wasn’t until Mark Richards, then an editor at John Murray Press (JMP), got in touch that things started to look up. Richards proposed leasing the UK rights from Soho Press and both Slow Horses and Dead Lions were published in paperback by JMP. And then reprinted. “The first time round nothing much happened” Herron says. “They didn’t sell. But Mark said, ‘Well, we’re going to keep doing this until they sell, until people pay attention’.”  Richards’ deep conviction about the books and unshakable belief in his author was validated when book three, Real Tigers, was published in hardback to phenomenal reviews.

Herron has now been a published author for 20 years. The eighth in the Slough House series, Bad Actors, achieved his first Original Fiction number one in May 2022. Slow Horses is a now a starry TV series for Apple TV, with Gary Oldman and Kristin Scott Thomas in the lead roles. And last year Herron won the crime novel of the year at Harrogate for Slough House, the seventh in the series, after five appearances on the shortlist in six years.