Few recent spy series have captured readers quite like Slow Horses.
Originally written by Mick Herron, the books follow the misfits, failures, and cast-offs of British intelligence who find themselves banished to Slough House—a crumbling administrative outpost for disgraced MI5 agents. Officially, they’re still employed. Unofficially, they’re expected to become so bored that they resign.
Unfortunately for MI5, the inhabitants of Slough House have a habit of stumbling into real conspiracies.
Thanks to the hugely successful Apple TV adaptation starring Gary Oldman as the unforgettable Jackson Lamb, the series has found a whole new audience. If you’ve recently finished binge-watching Slow Horses and want to start the books, here’s the complete reading order.
Slow Horses Books in Order
1. Slow Horses (2010)
Slough House is the outpost where disgraced spies are banished to see out the rest of their derailed careers. Known as the ‘slow horses’ these misfits have committed crimes of drugs and drunkenness, lechery and failure, politics and betrayal while on duty.
In this drab and mildewed office these highly trained spies don’t run ops, they push paper. Not one of them joined the Intelligence Service to be a slow horse and the one thing they have in common is they want to be back in the action.
When a boy is kidnapped and held hostage, his beheading is scheduled for live broadcast on the net. And whatever the instructions of their masters at the Intelligence Service headquarters, the slow horses aren’t going to just sit quiet and watch.
2. Dead Lions (2013)
In the Intelligence Service purgatory that is Slough House, where spies mockingly called the slow horses are sent to finish what is left of their careers, their boss Jackson Lamb is on his way Oxford. A former spook has turned up dead on a bus.
Not an obvious target for assassination, Dickie Bow was a talented streetwalker back in the day. Good at following people, bringing home their secrets. Dickie was in Berlin with Jackson Lamb. Now Lamb’s got his phone, on it the last secret Dickie ever told, and reason to believe an old-time Moscow-style op is being run in the Intelligence Service’s back-yard.
Once a spook, always a spook, and Dickie was one of their own. To unearth Dickie’s dying secret Jackson Lamb and his crew of no-hopers is about to go live.
3. Real Tigers (2016)
Slough House is the Intelligence Service outpost for failed spies, former high-fliers now dubbed the ‘slow horses’. Catherine Standish, one of their number, worked in Regent’s Park long enough to understand treachery, double-dealing and stabbing in the back, and she’s known Jackson Lamb long enough to have learned that old sins cast long shadows. And she also knows that chance encounters never happen to spooks, even recovering drunks whose careers have crashed and burned.
What she doesn’t know is why anyone would target her.
So whoever’s holding her hostage, it can’t be personal. It must be about Slough House. Most likely, it’s about Jackson Lamb. And say what you like about Lamb, he’ll never leave a joe in the lurch.
He might even be someone you could trust with your life.
4. Spook Street (2017)
The ‘Old Bastard’ raised his grandson to be a hero, not a slow horse. Now, far from joining the myths and legends of Spook Street, River Cartwright is part of Jackson Lamb’s team of pen-pushing no-hopers at Slough House. Which doesn’t mean he won’t ditch everything and go rogue when his grandfather comes under threat.
Lamb worked with Cartwright back in the day, and knows better than most that this is no innocent old man. So when a panic button raises the alarm at Intelligence Service HQ, it’s Lamb who’s called on to identify the body. And it’s Lamb who’ll do whatever’s necessary to protect an agent in peril.
5. London Rules (2018)
Tasked with protecting a beleaguered Prime Minister, he’s facing attack from all directions: from the showboating MP who orchestrated the Brexit vote, and now has his sights set on Number Ten; from the showboat’s wife, a tabloid columnist, who’s crucifying Whelan in print; and especially from his own deputy, Lady Di Taverner, who’s alert for Claude’s every stumble. Meanwhile, the country’s being rocked by an apparently random string of terror attacks.
Over at Slough House, the last stop for washed up spies, the crew are struggling with personal problems: repressed grief, various addictions, retail paralysis, and the nagging suspicion that their newest colleague is a psychopath. But collectively, they’re about to rediscover their greatest strength – making a bad situation much, much worse.
6. Joe Country (2019)
Catherine Standish is buying booze again, Louisa Guy is raking over the ashes of lost love, and new recruit Lech Wicinski, whose sins make him outcast even among the slow horses, is determined to discover who destroyed his career, even if he tears his life apart in the process.
With winter taking its grip Jackson Lamb would sooner be left brooding in peace, but even he can’t ignore the dried blood on his carpets. So when the man responsible for killing a slow horse breaks cover at last, Lamb sends his crew out to even the score.
This time, they’re heading into joe country. And they’re not all coming home.
7. Slough House (2021)
Slough House – the crumbling office building to which failed spies, the ‘slow horses’, are banished – has been wiped from secret service records.
Reeling from recent losses in their ranks, the slow horses are worried they’ve been pushed further into the cold, and fatal accidents keep happening.
With a new populist movement taking a grip on London’s streets, the aftermath of a blunder by the Russian secret service that left a British citizen dead, and the old order ensuring that everything’s for sale to the highest bidder, the world’s an uncomfortable place for those deemed surplus to requirements. The wise move would be to find a safe place and wait for the troubles to pass.
But the slow horses aren’t famed for making wise decisions.
8. Bad Actors (2022)
A key member of a Downing Street think-tank has disappeared without a trace.
Claude Whelan, one-time First Desk of MI5’s Regent’s Park, is tasked with tracking her down. But the trail leads straight back to Regent’s Park HQ itself, with its chief, Diana Taverner, as prime suspect. Meanwhile her Russian counterpart has unexpectedly shown up in London but has slipped under MI5’s radar.
Over at Slough House, the home for demoted and embittered spies, the slow horses are doing what they do best: adding a little bit of chaos to an already unstable situation.
In a world where lying, cheating and backstabbing is the norm, bad actors are bending the rules for their own gain. If the slow horses want to change the script, they’ll need to get their own act together before the final curtain.
9. Clown Town (2025)
MI5’s First Desk, Diana Taverner, doesn’t appreciate threats.
So when those involved in a covert operation during the height of the Troubles in Northern Ireland threaten to expose the ugly side of state security, Taverner goes on the offensive. And when that happens, people get hurt.
Over at Slough House, the repository for failed spies, the slow horses are hard at work: belittling each other, pushing paper, and marking time. Their boss, Jackson Lamb, wants them at their desks, but the slow horses are always looking for a way back on to Spook Street.
Meanwhile, another slow horse, River Cartwright, is waiting to be passed fit for work. At a loose end, and with his grandfather – a legendary former spy – long dead, River investigates the secrets of the old man’s library, and a mysteriously missing book. What stories will it hold? And who wants those stories to stay silent?
After all, spies lie, they betray, it’s what they do.
Should You Read the Slow Horses Books in Order?
Absolutely.
While each novel has its own central plot, the series rewards readers who follow the characters from the beginning.
Part of what makes the books so compelling is watching the relationships develop over time. Failures become heroes. Heroes become liabilities. People you dislike in one book suddenly become your favourites three novels later.
And then there’s Jackson Lamb.
Quite possibly one of the greatest characters in modern crime fiction.
Reading the books in order allows you to appreciate how Herron gradually builds both the team and the wider world of British intelligence.
Who Is Jackson Lamb?
It’s impossible to talk about Slow Horses without mentioning Jackson Lamb.
Officially, he’s the head of Slough House.
In practice, he’s rude, unhygienic, perpetually offensive, and seemingly incapable of behaving like a normal human being.
He’s also one of the sharpest intelligence officers in the country.
The genius of the character is that both things are true at the same time.
Gary Oldman’s portrayal has deservedly received enormous praise, but the character was already a standout on the page long before the television adaptation arrived.
Why London Fans Will Love the Series
One of my favourite things about Slow Horses is how recognisably London it feels.
You can often find yourself playing a strange game while reading:
“Hang on. I know exactly where that is.”
Slough House itself sits near Aldersgate, on the edge of the City and within sight of the Barbican. Once you know the area, it’s difficult not to picture the characters shuffling through those streets.
The books are packed with locations that feel genuinely lived in rather than researched for a tourist brochure.
For readers who enjoy spotting familiar places, that’s part of the fun.
Are the Books Better Than the TV Series?
The answer depends on what you’re looking for. The television adaptation is exceptionally good. Few readers would argue otherwise.
But the books have room to breathe.
Herron’s humour feels even sharper on the page, and many of the supporting characters receive more development than the show can realistically provide.
The best answer is probably the least satisfying one: If you enjoy the show, read the books. If you enjoy the books, watch the show.
There’s plenty to appreciate in both.
Final Thoughts
If you’re looking for a spy series to lose yourself in, Slow Horses is one of the easiest recommendations I can make.
The books are clever without being pretentious, funny without trying too hard, and packed with characters you’ll remember long after you’ve finished reading.
Just don’t be surprised if you find yourself wandering through the City afterwards, glancing at office buildings and wondering whether a group of disgraced intelligence agents might be hiding upstairs.
In London, it almost feels plausible.