Mick Herron had been writing about Jackson Lamb and the misfit M15 agents of Slough House for more than a decade before the Apple TV+ series Slow Horses brought them a larger, even more adoring audience. The latest installment, Clown Town (Soho Crime, September 9), features the head of British intelligence being blackmailed by a former member of Parliament, among other complications. As our starred review asks, “Since all these developments are filtered through the riotously cynical lens of Herron’s imagination…what could possibly go wrong?” Herron answered our questions by email.

Tell readers, briefly, what Clown Town is about.

The new book is about a group of former agents who were involved in a controversial operation in Northern Ireland at the height of the Troubles and are seeking reparation for what they see as the damage done to themselves and their careers as a result. At the same time, River Cartwright—not yet passed fit-to-return-to-work after the toxic harm done to him in Slough House—is looking into the disappearance of a book from his late grandfather’s library. As these two plot strands come together, the remaining slow horses are caught up in the resulting net.

Has anything changed about writing the books since the TV series began?

I don’t think so. I was well established in writing the series before filming began, let alone streaming. Though it’s true that Bad Actors, the first of the novels to be written since shooting started, is full of imagery borrowed from TV, cinema, and theater. I might not have gone down that route without the experience of being on set.

What inspired you during the writing of the book? What were you reading, listening to, watching?

I read pretty much constantly. I keep a list of what I’ve been reading these days, and during the 18 months or so that I was writing Clown Town I read something like 170 novels. I won’t list them all here. I listen to jazz or contemporary classical: Omar Sosa was a favorite during this period; the Tarkovsky Quartet was another. As far as TV goes, I watch pretty much exclusively drama (I get my news from radio and print). The police show Blue Lights—set in Northern Ireland, as it happens—was one of the best things I saw during that time, one of those shows which focuses on character development as much as plot. Though I’d add that I wouldn’t call any of these things “inspirational.” They’re just part of daily life.

Where and when did you write the book? Describe the scene, the time of day, the necessary accoutrements or talismans.

I try to maintain a 9-to-5 working day. I need to be in my own writing space (I don’t work anywhere else) and I need my laptop, but that’s all. I don’t have talismans—one of those words that looks very odd in the plural. (“Talismen”?)

What fall release(s) are you most eager to get your hands on?

Philip Pullman’s The Book of Dust: The Rose Field. It’s been a long time coming.

Laurie Muchnick is the fiction editor.