Clown Town

The ninth installment of the Slough House series opens with a prologue. An unnamed man, a former Irish Republican Army (IRA) enforcer who secretly served as a British intelligence informer, wakes in retirement to find himself bound with a tyre against his skull. Someone asks, "Any final observations?", the same words his victims heard (3). His head is crushed.

The story shifts to Slough House, a decrepit London building that serves as a dumping ground for disgraced agents of MI5, Britain's domestic intelligence service. Known as "slow horses," these agents endure soul-crushing busywork designed to make them resign. The roster includes Catherine Standish, the office manager and a recovering alcoholic; Shirley Dander, a combative agent; Roddy Ho, a gifted hacker; Lech Wicinski; Louisa Guy, haunted by the death of her former colleague and lover Min Harper; and Ashley Khan, the newest arrival. Their boss is Jackson Lamb, a slovenly, caustic former Cold War field agent.

River Cartwright, another slow horse recovering from near-fatal Novichok poisoning, tells Sid Baker, with whom he shares a flat, about an email from a researcher at an Oxford college. A book visible in a video of River's late grandfather David Cartwright's study is missing from the collection being catalogued, and no record of the book or its author exists.

Diana Taverner, the head of MI5's Regent's Park headquarters, faces her own crisis: Former Home Secretary Peter Judd's PR firm is secretly bankrolled by Chinese money, and Taverner used funds routed through Judd to finance an off-the-books act of vengeance, giving Judd leverage over her. She has received an anonymous email containing a recording of classified voices. Taverner summons Lamb and gives him three items: an anonymous grievance she wants Roddy to trace; the news that River will be dismissed because his poisoning occurred off-duty; and the information that Louisa is being recruited by Devon Welles, a former MI5 officer running a private protection firm. Her true motive is to ensure Lamb relays River's dismissal directly, leaving him desperate and open to manipulation.

River drives to Oxford and meets Charles Stamoran, known as "Stam," a retired agent in his seventies who once worked with David Cartwright. Stam admits he took the missing item, which was not a book but a hollow box disguised as a volume, used by spies to conceal secrets. He claims it contained pornography, which he destroyed to protect David Cartwright's reputation.

In truth, Stam has summoned his old crew, the "Brains Trust," former operatives Al Hawke, Avril Potts, and Daisy Wessex, to a nearby safe house. The box-safe contained a recording of the classified meeting that approved the decommissioning of Operation Pitchfork. Pitchfork was the code name for Dougal Malone, the enforcer from the prologue: a rapist and murderer who served as a British intelligence asset. The Brains Trust handled Malone during the Troubles in Northern Ireland. After the Good Friday Agreement, Malone was pensioned off while the Brains Trust was cast aside. Stam proposes blackmailing the Park, as Regent's Park is commonly known, by threatening to release the recording, and reveals he has already sent an extract to Taverner.

Back in London, Lamb discovers that Taverner instructed the Park's medical officer to fail River's evaluation, proving the dismissal is strategic. He deduces Taverner wants River desperate enough to accept an off-book assignment and tasks Louisa with learning her plans. Louisa, weighing Devon's job offer, realizes she has decided to leave Slough House.

River, concluding that his grandfather would never have hidden pornography among his beloved books, returns to Oxford but cannot find Stam. Meanwhile, Taverner meets Sid and offers a deal: If Sid delivers an envelope to Stamoran, Taverner will reverse River's dismissal. Sid accepts, knowing she is being used but believing she has no better option.

At the safe house, Daisy attacks Sid reflexively upon arrival. Stam, realizing Taverner has traced him, evacuates the group and abandons Sid at a motorway service station without her phone. River and Louisa break into the empty safe house and find Sid's phone but no occupants. MI5 internal security officers arrive. River punches one, and he and Louisa flee but are caught and released after Lamb intervenes.

Stam drives to a London flat, unaware that Avril has hidden a tracker in his car. There, Taverner reveals what he never knew: Avril, Al, and Daisy murdered Malone themselves, crushing his head with a Land Rover to make the killing look like an IRA reprisal. She threatens to make the murder charge public unless Stam cooperates. Her demand: Stam must go to Nob-Nobs, a Shoreditch nightclub where Judd will be waiting alone for a fabricated meeting, and kill him.

The slow horses piece together the scheme and agree to intervene despite Lamb's order to stand down. Catherine warns them to be careful. They race to the darkened nightclub. River and Sid find Judd inside and urge him to leave. Stam enters with a gun. River steps between them. Avril and Al arrive, trying to talk Stam down. Ash hits the lights, and Stam collapses from a massive stroke. Al scoops up the fallen gun and fires at Judd, but Ash dives in front and takes the bullet. Louisa tackles Al from behind. Daisy slashes Louisa's throat with a blade.

Louisa is dead. Ash is critically wounded. Stam is dying. Al and Daisy vanish.

Lamb confronts Taverner at the graveyard of St. Leonard's, the Spooks' Chapel, and demands her resignation. Taverner refuses, insisting she is indispensable and dismissing the slow horses' losses as footnotes. Lamb tells her he intends to "burn her fucking house down" (206). He then visits Devon and lies, claiming Judd funded the team that killed Emma Flyte, a former colleague Devon admired. Devastated, Devon provides the kill code to Taverner's home security system.

Lamb briefs the remaining slow horses on his plan. Catherine urges them not to participate, warning that grieving people make reckless decisions. They proceed regardless. River collects Judd, whom Devon has convinced to attend a negotiated meeting, and delivers him to Taverner's Notting Hill home, unlocked via the kill code. Inside, Lamb waits with a gun from Taverner's safe. Judd offers Lamb a lavish retirement funded by Chinese contacts in exchange for preserving the status quo. Lamb says, "Not for my joes" (323), and shoots him. He wipes the gun, returns it to the safe, and leaves. Roddy has disabled the surrounding CCTV cameras.

Taverner arrives home to find police, summoned by an anonymous tip. Judd's body lies in her sitting room; the murder weapon is in her safe. Judd had programmed a posthumous email detailing their compromising dealings, which reaches the Prime Minister. A former First Desk is appointed to take over MI5.

Stam dies in hospital with Avril and Sid at his bedside. Al and Daisy disappear entirely. Avril watches the safe house from across the road, thinking she sees movement in a window but choosing not to cross, preferring uncertainty to finality.

Ash regains consciousness in a hospital bed. She opens her eyes and says, "Mum?"

Catherine returns to Slough House after the others gather at a pub to toast their fallen. She tells Lamb she may not come in tomorrow. He replies, "Yes you will." When she asks why he is so certain, he says, "Because I can read you like a book" (337).