Many of TV and film's greatest espionage tales – from the adventures of James Bond to the Cold War thrillers of John le Carré – have originated on the printed page and the same is true of Slow Horses, the offbeat spy series from Apple TV+ that earned a rave response from audiences and critics when it launched on the streaming platform in April.


The good news for those fans is that a second season was shot back-to-back with the first, meaning the Slow Horses cast are returning for new episodes just seven months after the show's debut outing closed out its run.

But if you're hungry for even more from Jackson Lamb and his misfit team of agents, then you might want to dig into the source material. Here's all the essential info you'll need on the Slow Horses books, featuring exclusive insights from author Mick Herron.

Is Slow Horses based on a book?

Yes – the television series is based on the Slough House series, a long-running collection of books featuring the brilliant but irascible Jackson Lamb, who's played on screen by Gary Oldman.

The first season of Slow Horses was based on the first book in the series, while the second season is based on the follow-up book, Dead Lions.

“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 "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."

How many books are there in the Slough House series?

There are currently eight books in the Slough House series, with the most recent being released on 10th May 2022.

Here's the full list of Slough House novels in order.

  1. Slow Horses (2010)
  2. Dead Lions (2013)
  3. Real Tigers (2016)
  4. Spook Street (2017)
  5. London Rules (2018)
  6. Joe Country (2019)
  7. Slough House (2021)
  8. Bad Actors (2022)

Alongside the eight novels, Herron has also written three novellas in the series - The List (2015), The Marylebone Drop (2018) and The Catch (2020).

Meanwhile, Herron's novels Reconstruction (2008) and Nobody Walks (2015), while not officially part of the series, take place in the same world and include some of the same characters.

There’s no word if Slow Horses’ success will see these spin-off books also brought to screen in the near future. "There haven’t been discussions about filming them, but it certainly remains a possibility," said Herron. "For the time being, it's the Jackson Lamb series which is being focused upon."

Does Jackson Lamb feature in all of the novels?

Gary Oldman as Jackson Lamb in Slow Horses
Gary Oldman as Jackson Lamb in Slow Horses. Apple TV+

Lamb appears in all of the Slough House novels, meaning there should be plenty of scope for Gary Oldman to return as the character time and again. However, in an exclusive interview with, Oldman revealed that Herron hadn't always intended it to be that way.

Oldman explained: "Lamb was never originally going to appear. Lamb was up somewhere on the eighth floor, or the seventh floor or somewhere in the building and that he was such a sort of legend that people talked about him, but he never appeared.

More like this

"And Mick said that he wrote one scene with Lamb and once he gave him the voice, he went, 'Oh no, this guy's too interesting,' and that's how the whole thing shifted - which is fascinating to me that he was going to be an off-stage character."

Will the Apple TV+ series adapt more of the books?

It will indeed. When the series was first announced, Deadline reported that 12 episodes were being shot, with the latter six focusing on the second novel, Dead Lions.

In June 2022, Apple TV+ announced that Slow Horses would also be returning for a third and a fourth season.

The even better news is that filming on the third season is already underway, meaning it could arrive on our screens before the end of 2023.

The third season of Slow Horses will see Lamb and his allies attempt to foil a rogue agent when one of their own is kidnapped, while the fourth opens with a bombing that detonates personal secrets, "rocking the already unstable foundations of Slough House".

Herron previously told that while he's unaware of any long term plans to develop the whole run of novels for television, he’d be “delighted” if there were.

"I'd be delighted if that does happen – everybody seems to be happy with the work done so far, but we've no way of knowing what the future holds. I don't know – but I do know that barring some unforeseen catastrophes, books one to four will be on television screens within the next couple of years."

Slow Horses season 2 debuts new episodes weekly on Apple TV+ – you can sign up to Apple TV+ here. You can also buy Mick Herron's book Dead Lions now.

Looking for something else to watch? Check out our Drama hub for more news and features, or visit our TV Guide or Streaming Guide for more to watch.


The latest issue of Radio Times magazine is on sale now – subscribe now. For more from the biggest stars in TV, listen to the Radio Times View From My Sofa podcast.