Slow Horses
What is the premise of Slow Horses?
Who is Jackson Lamb in Slow Horses?
What is the significance of Slough House in the series?
What awards has Slow Horses won?
News •
In a cramped, crummy office tucked away in an alley near London’s Aldersgate Street, a band of MI5 agents—discarded from the agency’s elite ranks but not dismissed—grinds through tedious administrative work and other humdrum tasks. Motley though the group is, its members have one thing in common: They made a blunder or committed an offense during their MI5 careers for which they have been cast off from the team of security service agents at the Regent’s Park headquarters and tossed into the Slough House office to slog away for the rest of their careers. This is the fictional world of the British espionage series Slow Horses (2022– ), based on novelist Mick Herron’s Slough House series and streamed on Apple TV.
To the rest of MI5, the rejects are “slow horses,” the derogatory nickname from which the series takes its title. Ironically, the series begins with an adrenaline-fueled, fast-paced chase sequence, only for it to turn out to be a training exercise that the assigned agent bungles, immediately earning a one-way ticket to Slough House.
(Fair warning: Spoilers ahead!)
" height="20" alt="HEW Logo">
Main characters
The glossy, high-tech, bureaucratic world of The Park—as the headquarters is called—populated by sharply dressed officers driven by ambition, private agendas, and the pursuit of power, is in sharp contrast to the largely disorganized, mostly instinctive, and somehow more humane and recognizably real world of Slough House. This stark difference is brought alive on-screen by the distinctive characters from the two sides of MI5.
Slough House
- Jackson Lamb (Gary Oldman): Once an ace agent, Lamb now leads the slow horses as the self-exiled head of Slough House—a posting he chose. He asked for it after carrying out an order to kill his former friend and mentor Charles Partner (James Faulkner), the former First Desk (head of MI5), whose treachery had been uncovered. Beneath Lamb’s unkempt appearance, crude manners, noxious flatulence, and stinging remarks lies one of the sharpest minds in MI5 and a man fiercely protective of his brood of misfits. As he says of them: “They’re a bunch of…losers. But they’re my losers.”
- River Cartwright (Jack Lowden): The young, intelligent River is not the quintessential protagonist. A fundamentally decent man and the grandson of renowned former MI5 officer David Cartwright (Jonathan Pryce), River is also prone to mistakes, failures, and flashes of ego. After botching the training exercise that opens the series, he finds himself stuck in what appears to be the graveyard of his career, answerable to a boss whose every other remark is a jibe. Restless to prove useful, River longs to do actual sleuthing. What endears him to viewers is the balance between his weaknesses and honest emotions, his ambition and good intentions, and his growing maturity, even when his instincts sometimes outrun his judgment.
- Catherine Standish (Saskia Reeves): The calm, patient, and maternal Standish is not an ex-agent but comes with years of experience and knowledge, having been the secretary to former First Desk Charles Partner. Her alcoholism, along with her association with Partner, has landed her in Slough House as office administrator. With her discerning nature, she patiently anchors Lamb and also holds the rest of Slough House together.
- Louisa Guy (Rosalind Eleazar): Louisa is an efficient, levelheaded, and sensible officer in Lamb’s retinue. Her slipup: She lost track of a gun smuggler she was following, costing MI5 the chance to recover a cache of smuggled weapons. Although deeply affected by her tarnished reputation and downgraded position, she remains committed to Slough House and its operations, carrying them out with precision and diligence. Her quiet but meaningful relationship with fellow agent Min Harper reveals her sensitive, vulnerable side and gives the story added emotional weight.
- Roddy Ho (Christopher Chung): Vain to the point of exasperation, computer genius and hacker Roddy did not have to make an error to be thrown out of MI5 headquarters. His insufferable self-praise was intolerable enough, but it was his phenomenal technical abilities that ultimately worked against him as the superiors at MI5 feared that his skills might be misused, putting MI5 at risk. Roddy is exceptional at his work, but his thoroughly unpleasant personality almost always irks his colleagues.
- Min Harper (Dustin Demri-Burns): Good-natured Min’s expulsion from The Park was on account of an absolute blooper—he accidentally left a device containing classified MI5 information on a train. He is a well-meaning man, if a tad comical, who falls in love with Louisa. What follows is a warm, understated romance, as the two also work together, until Min is murdered, though his death is made to look like a hit-and-run accident at first.
- Shirley Dander (Aimee-Ffion Edwards): Shirley joins fellow slow horses after having punched her superior—not once, but twice. The first punch followed an unwanted advance; the second came after he told her that she hit like a girl, a reaction entirely in keeping with her fiery temperament. Tough, dogged, and unwavering in her loyalty to those she supports, Shirley rarely backs down after she sets her mind on something. However, she struggles with drug addiction.
- Marcus Longridge (Kadiff Kirwan): When a tactical agent, no matter how skilled, fails to overcome a severe gambling problem and places a bet while on active duty, MI5 does not forgive. The price that Marcus pays is a transfer to Slough House, of course. An expert in hand-to-hand combat, Marcus becomes a steady, rational presence in Slough House, often teaming with Shirley on duty and tempering her volatile energy. His sudden death cuts short one of the team’s most effective partnerships and deals a particularly devastating blow to Shirley.
- J.K. Coe (Tom Brooke): Earphones plugged in and the world shut out is how Coe navigates his time at Slough House. His reclusive nature is matched by an almost permanently deadpan expression. Yet his observations, when he cares to share them, are incisive. Coe, who worked in the psychological evaluation department at headquarters, has been transferred to Slough House after suffering severe trauma. When Coe does act, it is with unnerving precision, such as when he stops Shirley from killing the mercenary Patrice (Tom Wozniczka) and then kills Patrice himself, sparing Shirley from committing murder.
- Sidonie (Sid) Baker (Olivia Cooke): Capable, observant, and seemingly out of place among the slow horses, Sid has secretly been assigned to keep an eye on River. Her stint at Slough House is cut short when another slow horse, Jed Moody, shoots her during what is called the Hobden operation.
- Struan Loy (Paul Higgins): Talkative and eager for company, Struan was sent to Slough House after circulating an inappropriate email about First Desk Ingrid Tearney and then lying about it. When The Park pressures him to turn against Lamb and his colleagues to pin MI5’s failure on Slough House, Struan ultimately caves. Later, he is ruthlessly murdered by two assassins, who try to make his death look like an accident.
- Jed Moody (Steven Waddington): A former member of MI5’s internal security unit, Moody is a surly and intimidating presence at Slough House. Drawn into an off-the-books operation orchestrated by The Park, he shoots Sid and later dies after a struggle sends him tumbling down the stairs of Slough House.
Regent’s Park (MI5 headquarters)
MI5 is an intelligence agency charged with internal security and domestic counterintelligence activities of the United Kingdom. It is authorized to investigate any person or movement that might threaten the country’s security. Although MI5 is responsible for domestic counterespionage, it has no powers of arrest, which devolve instead on Scotland Yard.
MI6 is the British government agency responsible for the collection, analysis, and appropriate dissemination of foreign intelligence. It is also charged with the conduct of espionage activities outside British territory.
- Diana Taverner (Kristin Scott Thomas): A cold, calculating woman, Taverner is the deputy director general (Second Desk) and head of operations of MI5. She later ascends to First Desk. Almost regal in her demeanor, she has a commanding presence, planning and executing schemes that she thinks will benefit both MI5 and her ambitions. When required, she does not hesitate to bend the rules and use (or discard) Slough House operatives as she pleases.
- Nick Duffy (Chris Reilly): Duffy is the ruthlessly efficient and aggressive head of the Dogs—MI5’s internal security and tactical unit. One of The Park’s chief enforcers, he is fiercely loyal to MI5 and handles many of MI5’s most sensitive jobs. Taverner relies heavily on him but treats him more as a useful instrument. However, when Duffy attacks Marcus during a confrontation with Slough House agents, Louisa hits the chief of the Dogs in the head, leaving him in a coma.
- Ingrid Tearney (Sophie Okonedo): MI5’s director general, or First Desk, during the earlier seasons, Tearney is sharp, uncompromising, and politically astute. However, incriminating evidence against her related to an operation in Istanbul and her attempts at a cover-up prove to be her undoing, and she is discharged from her duties.
- Claude Whelan (James Callis): Whelan succeeds Tearney as First Desk after she is disgracefully dismissed. He has the title and authority but is frequently outmaneuvered by Taverner and overwhelmed by the realities of the job.
- James (“Spider”) Webb (Freddie Fox): A smug, ambitious Park agent, Webb is River’s former friend-turned-rival. River believes that Webb, perhaps deliberately, misled him during the training exercise, which resulted in the debacle. Webb, however, denies the allegation and takes pleasure in disparaging River and the slow horses. He later becomes head of vetting and remains convinced of his own superiority. His habitual haughtiness ultimately proves fatal. He makes a cruel taunt during an encounter, provoking a punch that sends his head into a car window, killing him.
- Molly Doran (Naomi Wirthner): Molly is a formidable senior archivist and guardian of MI5’s records at Regent’s Park. Abrasive and difficult to impress, she possesses an invaluable knowledge of MI5’s buried history. She and Lamb know each other well, and she helps him with crucial information.
Plot summary
Mick Herron began as a detective-fiction writer while working as a copy editor, turning to the espionage genre after the 2005 London bombings. His first spy novel, Slow Horses (2010), attracted little attention until editor Mark Richards republished it through John Murray. The second novel in the series, Dead Lions (2013), won the Gold Dagger Award the same year, launching Herron’s Slough House series to international success. Here are the novels that each season of Slow Horses is based on:
- Season one: Slow Horses (2010)
- Season two: Dead Lions (2013)
- Season three: Real Tigers (2016)
- Season four: Spook Street (2017)
- Season five: London Rules (2018)
- Season six: Joe Country (2019) and Slough House (2021)
- Season seven (planned for 2027 release): Bad Actors (2022)
- Season eight (announced): Clown Town (2026)
Picture this: The suave MI6 operative James Bond in an impeccably tailored tuxedo, whizzing off in an Aston Martin; Mission: Impossible superspy Ethan Hunt tinkering with high-tech gadgets and pulling off sensational stunts; or gritty CIA agent Jason Bourne acing it in a bout of hand-to-hand combat. Now strip all that away, and you land in the world of Slow Horses, a show that deliberately and gleefully subverts the glitz and glamour usually associated with the on-screen world of espionage. In their place are flawed geniuses and idiosyncratic personalities thrust together in the dregs of intelligence services, operating like a dysfunctional family under its disreputable patriarch. Yet the show delivers an intense spy drama—Lamb is no less astute and capable than Bond or any of his other fictional counterparts—while subtly balancing the action and suspense with dry office humor and the messy humanity of its people in each six-episode season.
Season one: The rather dull and listless life at Slough House is unexpectedly stirred into action when a nationalist group, the Sons of Albion, kidnaps British-Pakistani student Hassan Ahmed (Antonio Aakeel). The slow horses uncover that the kidnapping is actually a false flag operation engineered by Taverner to elevate MI5’s public image. However, when Taverner’s plan is derailed, she desperately tries to cover her tracks, while Lamb and his team go rogue to rescue the hostage. They manage to save Hassan and expose Taverner’s scheme, leaving her scrambling to contain the fallout.
Season two: This season turns to the remnants of the Cold War. Former field agent Richard (Dickie) Bow’s (Phil Davis) suspicious death on a bus reveals a conspiracy involving “cicadas”—hidden Russian sleeper agents. As Lamb investigates the killing, River goes undercover, visiting a flying club where he exposes a seemingly ordinary family matriarch as an active sleeper spy. Meanwhile, Webb recruits Min and Louisa to provide security for a meeting between MI5 and a Russian oligarch’s team, an assignment that proves fatal for Min.
The trusted destination for professionals, college students, and lifelong learners.
SUBSCRIBE
Season three: A “Tiger Team” led by former MI5 operative Sean Donovan (Ṣọpẹ́ Dìrísù) kidnaps Standish as part of an authorized test of MI5’s security, although Slough House is kept in the dark. With Standish’s life apparently at risk, River is ordered to break into Regent’s Park and steal the prime minister’s vetting file while Lamb and the rest of Slough House work to rescue her. After River completes the task successfully, Donovan goes rogue. He refuses to release Standish and demands access to a secure archive to get hold of Footprint, a top-secret file proving that Tearney covered up a disastrous operation in Istanbul and ordered the killing of Donovan’s girlfriend, Alison Dunn (Katherine Waterston), when she tried to expose it. Once the slow horses understand Donovan’s motive, they help him retrieve the evidence. Taverner takes advantage of the situation and uses the eventual leak to bring about Tearney’s downfall.
Season four: A car bomb goes off at a shopping center, setting the story in motion. Later, an assassin posing as River arrives at the home of David Cartwright (River’s grandfather) to kill him but is shot by David instead. River’s investigation leads to Frank Harkness (Hugo Weaving), a former CIA officer who has fathered many sons with different women, raising the boys in a private compound in France as a private army of mercenaries. To his horror, River discovers that Harkness is his biological father. Harkness’s men hunt down people who could connect him to a decades-old MI5 secret and the shopping center bombing. One of the targets is David, and Marcus is killed defending him at Slough House. Harkness is finally captured, but not before revealing that he holds enough compromising material on MI5 to guarantee his release—a threat left dangling as the season closes.
Season five: A woman named Tara (Hiba Bennani) pretends to be romantically interested in Roddy and uses him to infiltrate MI5’s systems. She belongs to a terror cell led by Farouk (Monty Ben). The cell unleashes a string of attacks across London as part of a destabilization campaign. At one stage they target mayoral candidate Zafar Jaffrey (Nick Mohammed), prompting Slough House to protect him as well as rival candidate Dennis Gimball (Christopher Villiers), who is killed in a bizarre accident involving Coe and River. Meanwhile, as Whelan tries to control the situation, he is threatened by blackmail about an affair and later plots to make Slough House a scapegoat for MI5’s failures. Lamb leverages a damaging recording of Whelan to protect Slough House and force Whelan out of MI5, thus paving the way for Taverner to become First Desk.
Season six: The season begins on a sinister note. Struan is burned to death by two unknown assassins inside the shipping container he had been calling home; another former Slough House agent is drowned by the same pair; and then River becomes their next target—all suggesting that someone might be systematically targeting people connected with Slough House. Apart from many returning characters, this season, which premiered on September 16, is set to introduce Doctor Who star Lenny Rush, although details of his role are not yet known.
Production
On a rainy day in 2014, Herron attended back-to-back meetings—the first two soaking wet—with production houses interested in adapting his Slough House books. The final one was with See-Saw Films, and Herron chose to go with them. See-Saw sent the first two books, the only ones published at the time, to writer and stand-up comedian Will Smith, whose work on The Thick of It (2005–12) and Veep (2012–19), with biting humor and drama, made him a natural fit for the project. Smith was hooked immediately. He came aboard as the showrunner, executive producer, and lead writer of the series and thus began a close creative partnership with Herron, retelling the stories on-screen. Five years after See-Saw’s first meeting with Herron, Apple TV+ (later Apple TV) signed on as the streamer, and the show went on to become a major success on the platform. Smith stepped away from the series after the fifth season, handing over charge to Gaby Chiappe for season six and Ben Vanstone for season seven. The title track, “Strange Game,” written by the Rolling Stones lead singer Mick Jagger (who was already a fan of the books) and composer Daniel Pemberton and performed by Jagger, establishes the series’ offbeat, slightly sinister mood from the outset.
Reception and awards
Perhaps one of the most welcome endorsements for the series came from the real director general of MI5, Ken McCallum, who declared in 2026: “I happen, myself, to be a Slow Horses man.” Other notable admirers of the show are Microsoft cofounder Bill Gates and members of the British royal family, including Queen Camilla and Prince William. An average critic rating of 97 percent on Rotten Tomatoes, a wide international viewership, and sustained critical acclaim for its stellar ensemble cast, sharp writing, and blend of suspense and dark humor have established Slow Horses as one of television’s most celebrated spy dramas.
The series has been recognized by major television awards bodies. At the Emmy Awards, Will Smith won in the category of outstanding writing for a drama series for the episode “Negotiating with Tigers” in 2024; Adam Randall received the outstanding directing for a drama series award in 2025 for the episode “Hello Goodbye,” while Saul Metzstein won in the same category the following year for the episode “Scars.” The show had 23 Emmy nominations between 2024 and 2026. It has had similar success at the BAFTA Awards, winning the BAFTA TV Craft Awards for both sound and editing for fiction in 2024 and 2025, and best writer in the drama category in 2026, alongside a number of nominations. The writing has also been formally recognized: In 2023 and 2024 Herron and Smith won the USC Libraries Scripter Award for episodic television for “Failure’s Contagious” and “Negotiating with Tigers,” respectively, honoring the adaptation of Herron’s novels for the screen.