Who wrote Slow Horses, and what is the unmissable TV series based on?

Slow Horses premiered on Apple TV in April 2022 and has proved a huge hit with fans, boasting a 97% rating on Rotten Tomatoes and some stellar reviews from critics. The Guardian declared 'it’s wild how good Gary Oldman’s spy thriller is'. While Forbes calls Slow Horses 'a masterpiece of spy TV'. 

Based on the Slough House books, the plot of what will shortly end up on our pick of the best British crime dramas centres around a group of failed secret agents who have been thrown out of MI5’s headquarters for their incompetency, and banished to a dingy office in London's Barbican Centre. Gary Oldman leads the cast as Jackson Lamb, with Jack Lowden, Kristin Scott Thomas and Jonathan Pryce as part of his motley crew of disgraced agents. 

Each season of the show is based on a different novel in the Slough House series, written by Mick Herron. And with eight books in the collection, there's plenty of material for future TV series. 

Season four is in the works and should be released in December 2024, according to reporting from Screen Rant. Before we get our next fix of the espionage show that fuses spay action with dark comedy, we're delving into who wrote Slow Horses and the popular books that inspired the series.

Who wrote Slow Horses? 

Slow Horses, the TV show, was written by comedian, actor, novelist and screenwriter Will Smith, who adapted the famous novels for Apple TV. Will said of the project (via The Royal Television Society), "I first read it [Slow Horses] back in 2014 when there were only two books in the series. Mick Herron is about to start work on the ninth. I loved that it was funny as well as thrilling, that the characters felt so real and dimensional, and that it was in the spy genre but doing something new and different.

"There’s a moment early on in the first book where Mick follows all the characters home and gives you a glimpse into their personal lives. I’d never come across that in a thriller before and it felt as compelling as the action and plot twists. And also on a line-by-line basis, Mick is a terrific writer."

He continued: "The dialogue just sings. He can go for page after page without having to tell you who’s talking because the voices are so distinctive. All of that made it a dream to adapt. I was in from the first page.

The original Slow Horses novels are written by Mick Herron, a master of espionage fiction who was recently called the 'the best spy novelist of his generation' by the New Yorker. 

What is Slow Horses based on? 

Slow Horses is based on the Slough House series, a collection of books by Mick Herron. The first season of Slow Horses was based on the first book in the series written in 2010, also called Slow Horses. The second season was based on the follow-up book, Dead Lions, while season three was based on the third book, Real Tigers.

“Slow Horses was very faithful to the plot of the original book. That's probably less true in the next one for a variety of reasons,” Mick Herron told RadioTimes.com. 

"All the big changes to plots have been made with either my happy agreement or, sometimes, at my suggestion. There will be changes, but for me, the important things are the characters and the tone, which elides between comedy and sometimes tragedy.

"I've been very happy with the approach they're taking, and I certainly don't require the plotting to be step-to-step in line with the book, because what would be the point of that in the long run? We want to be more creative and carry on being creative with the adaptation."

The full list of books in the Slow Horses series is as follows: 

• Slow Horses (2010)
• Dead Lions (2013)
• Real Tigers (2016)
• Spook Street (2017)
• London Rules (2018)
• Joe Country (2019)
• Slough House (2021)
• Bad Actors (2022)

Shop the Slow Horses books that inspired the TV series