Some readers compare Mick Herron to John le Carré. But the similarity is puzzling. The 14 books to date in the Slough House series satirize British intelligence rather than celebrate or lament its excesses, as the work of Le Carré has done so ably. Diana Taverner, who is First Desk in Herron’s Security Service, or MI5, is amoral, self-seeking, and ruthless. She’ll stop at nothing to hold onto power. In any other context, she’d be the villain. And Jackson Lamb, who presides over Slough House, is a comic book caricature of a slovenly and foul-mouthed boss. Yet, taken together with the losers in his charge, the whole lot show great skill as counter-intelligence agents. More to the point, Herron has a lot of fun with their stories. And so do we as readers. Somehow, he immerses us in a tale that’s suspenseful, insightful about human nature, and endlessly enjoyable.
The more things change, the more they’re the same
In Clown Town, the 14th entry in Herron’s series, the mood is as grim and gray as the intermittent rain that spatters on London’s rooftops and slicks its sidewalks. Disgraced former Home Minister Peter Judd, long an evil presence in the background, has maneuvered Diana Taverner into accepting Chinese funding to bankroll an off-the-books operation. He is blackmailing her to bring pressure on the Cabinet to shift national policy to favor Chinese interests.
Meanwhile, the cast of characters at Slough House has continued to evolve. Jackson Lamb still rules the roost. But the clusterf**k that recently involved his charges has left one dead and Sid (Sidonie) Baker, River Cartwright’s love interest, reeling from a brain injury. And River himself is on sick leave and tending to Sid. At Slough House itself, only continuing characters Catherine Standish, Shirley Dander, Lech Wicinski. and Roddy Ho remain along with Jackson Lamb. A fresh-faced newbie, Ashley Khan, has joined them. She harbors the illusion that her brilliant performance will gain her readmission to headquarters at Regent’s Park. And none of them are prepared for the challenge when they set out on a new investigation against Jackson’s orders. Their target is an aging former spy who is blackmailing the Park to increase his pension. Unfortunately, they’re not the only one on the old man’s trail.
Clown Town (Slough House #14) by Mick Herron (2025) 352 pages ★★★★★
London’s gray skies and a crumbling building set the tone
Much of the action in Clown Town takes place at Slough House, a shoddy old building on Aldersgate Street. And Herron makes much of the place to set the novel’s tone. “If the murkiest of London’s depths are where its spooks congregate, Slough House—this being the name of the Aldersgate Street residence—is the lowest of the low; an administrative oubliette where the benighted moulder in misery. Their careers are behind them, though not all have admitted it.” As you can see, Mick Herron writes for a literate audience. Unlike so much popular spy fiction, the Slough House series is never dumbed down. Every page shows off Herron’s consummate skill as a writer.
Summary of the novel by Claude-AI
My artificial friend, the AI app Claude, settles on different aspects of the story in its summary. I’m reproducing it verbatim except for the three subheads I’ve added.
A darkly comic espionage saga
Clown Town is the ninth [novel] in Mick Herron’s acclaimed Slough House series, continuing the darkly comic espionage saga that inspired the Apple TV+ series Slow Horses. This gripping thriller centers on Jackson Lamb and his team of disgraced MI5 operatives known as the “slow horses,” caught between MI5’s shadowy past and uncertain future.
The story begins with a mystery surrounding the late David Cartwright, former head of MI5 and grandfather to River Cartwright. David Cartwright has posthumously donated his library to the Spooks’ College in Oxford, but now one of the books has gone missing—or perhaps never existed at all. River, currently on medical leave and awaiting clearance to return to active duty, finds himself with time to investigate the secrets hidden within his grandfather’s collection.
“Old spies aren’t much better than clowns”
The novel’s title reflects David Cartwright’s cynical observation to his grandson: “Old spies grow ridiculous, River. Old spies aren’t much better than clowns.” However, Herron explores how these aging operatives remain dangerously relevant, particularly when financial desperation drives them to extreme measures.
Meanwhile, at MI5 headquarters (the Park), First Desk Diana Taverner faces a significant crisis. An operation conducted during the height of the Troubles has exposed the brutal realities of state security, and those involved are now threatening to reveal damaging details. Ever the opportunist, Taverner devises a scheme to turn this threat to her advantage, requiring only the right person to serve as a scapegoat.
Will they all survive their latest caper?
Jackson Lamb, the sardonic and malodorous leader of Slough House, initially has no intention of deploying his team—his “clowns”—into this dangerous situation. However, when his operatives choose to ignore his directives and become involved anyway, Lamb finds himself reluctantly protective of his dysfunctional team. The novel’s tension builds around whether all of Slough House’s operatives will survive their latest misadventure, and Lamb’s promise of retribution if they don’t.
Clown Town is described as a “gripping, hilarious, and heartbreaking thriller” that showcases Herron’s signature blend of sharp wit and genuine emotional depth. The novel continues to explore themes of loyalty, redemption, and the personal costs of espionage work while delivering the series’ characteristic mix of dark humor and nail-biting suspense. Critics have praised Herron’s unique perspective on spycraft and his skill in creating complicated, empathetic characters.
About the author
Mick Herron published his first novel in 2003. It was the debut of a four-book series of detective novels. He began the Slough House series in 2010 with Slow Horses. Herron was elected a Fellow of the Royal Society of Literature in 2024. He got his feet wet first in poetry, then in detective fiction, before settling into the game of espionage.
Herron’s author website discloses that “Raised in Newcastle upon Tyne, Herron studied English Literature at Oxford, where he continues to live.”
For related reading
I’m tracking this series as new books appear at Following Mick Herron’s clever British spies at Slough House.
For a more realistic look at MI5, see Dame Stella Rimington’s Liz Carlyle series of top-notch espionage novels. Rimington, who died earlier this year, was the first female Director General of MI5. She held the job from 1991 to 1996.
You’ll find other great reading at:
- The 15 best espionage novels
- Good nonfiction books about espionage
- The best spy novelists writing today
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