50 free Slow Horses trivia questions with answers — entertainment quiz, new questions added Aug 2026.
Slow Horses turned Mick Herron's novels about MI5's rejects into one of the best-reviewed shows on television, with Gary Oldman's flatulent, brilliant Jackson Lamb presiding over Slough House and a schedule that somehow delivers a new series every year. These 50 questions cover the show and its source: the cast from Jack Lowden and Kristin Scott Thomas to Jonathan Pryce and Hugo Weaving, why each slow horse was banished, the Dogs and "Spider" Webb, the Sons of Albion, Upshott and Chieftain, which novel each series adapts, the single-director rule, the back-to-back shooting schedule, Emmy nominations and Rotten Tomatoes scores. The books get their due too: Barbican not Slough, the Gold Dagger for Dead Lions, Andy Dalziel as Lamb's model, Waterstones and Nancy Pearl rescuing the series, and the 7/7 commute that turned Herron into a spy novelist. Easy questions stick to the main cast and the premise; the hard tier asks about guest stars, directors and publishing history. Every answer is cited to a page we checked and comes with a short explanation that adds one more fact. Play it solo or print it for a spy-thriller night.
30 of 50 questions with answers and explanations. Play the quiz
Q 01Who plays Jackson Lamb?
Gary Oldman
He has been nominated for Golden Globes, BAFTAs, Emmys and SAG Awards for the role.
Q 02Which author wrote the novels the series is based on?
Mick Herron
His books have sold more than four million copies.
Q 03On which streaming service did the show premiere?
Apple TV+
It premiered on 1 April 2022.
Q 04What does Jackson Lamb affectionately call his agents?
Joes
The nickname hides a firm loyalty beneath the flatulence and insults.
Q 05Who adapted the novels for television and served as showrunner?
Will Smith
He is the English comedian and writer, not the Hollywood actor.
Q 06Who plays River Cartwright?
Jack Lowden
He earned an Emmy nomination for Supporting Actor in a Drama for series 3.
Q 07Who plays Diana Taverner?
Kristin Scott Thomas
Her character is known as "Second Desk" until a promotion at the end of series 5.
Q 08What is Diana Taverner's designation for most of the series?
Second Desk
She becomes First Desk, Director General, at the end of series 5.
Q 09Who plays River's grandfather David Cartwright?
Jonathan Pryce
David is a retired MI5 legend nicknamed "The Old Bastard".
Q 10Who is revealed to be River's biological father?
Frank Harkness
Hugo Weaving plays the ex-CIA mercenary.
Q 11Who plays Catherine Standish?
Saskia Reeves
Standish is the office administrator and a recovering alcoholic.
Q 12Why was Louisa Guy sent to Slough House?
She lost a tail on a suspect
Rosalind Eleazar plays her.
Q 13What is Roddy Ho's speciality?
Computers
Christopher Chung plays the arrogant former hacktivist.
Q 14Who plays Shirley Dander?
Q 21Who plays the ambitious politician Peter Judd?
Samuel West
Judd rises to become Home Secretary.
Q 22Which real politician did Herron cite as the basis for Peter Judd?
Boris Johnson
Herron says he is drawn to incompetence and things going wrong.
Q 23Who plays the bumbling Director General Claude Whelan?
James Callis
Whelan banishes records keeper Moira Tregorian to Slough House.
Q 24What is the name of the far-right group that kidnaps Hassan Ahmed in series 1?
Aimee-Ffion Edwards
Dander is physically capable but undone by drug and anger issues.
Q 15Who plays MI5 Director General Ingrid Tearney?
Sophie Okonedo
She appears in series 1 and 3 as "First Desk".
Q 16Why was Min Harper assigned to Slough House?
He left a secret disk on a train
Dustin Demri-Burns plays him in series 1 and 2.
Q 17Who plays Sidonie "Sid" Baker?
Olivia Cooke
She appears in series 1 and returns in series 6.
Q 18Why was Struan Loy banished to Slough House?
An inappropriate work email
Marcus Longridge is the one who gambles on the job.
Q 19What is the nickname of MI5's internal affairs and tactical unit?
The Dogs
Nick Duffy heads them in the early series, Emma Flyte later.
Q 20What is James Webb's nickname?
Spider
Freddie Fox plays the smug Regent's Park agent.
Sons of Albion
Hassan is a Leeds University student.
Q 25Who plays the former KGB agent Nikolai Katinsky in series 2?
Rade Šerbedžija
He lives in exile in London after defecting at the Cold War's end.
Q 26In which small village does much of series 2 take place?
Upshott
The Tropper family run the pub there.
Q 27Who plays disgraced ex-MI5 officer Dickie Bow in series 2?
Phil Davis
His real name is Richard Bough.
Q 28What is the private security firm at the centre of series 3?
Chieftain
Sly Monteith heads it.
Q 29Who plays Sean Donovan in series 3?
Sope Dirisu
Donovan was head of security at the British embassy in Istanbul.
Q 30Who plays Mayor of London Zafar Jaffrey in series 5?
Nick Mohammed
He is best known as Nate in Ted Lasso.