The first season of the spy drama, starring Gary Oldman as the unorthodox MI5 officer Jackson Lamb, arrived on Apple TV+ in April to widespread acclaim. The second season is due to arrive later this year and filming is about to start on the new run.
It was announced at the start of June the third and fourth books in Herron’s Slough House series – Real Tigers and Spook Street – would comprise the third and fourth seasons of the espionage series.
In an exclusive interview with RadioTimes.com, Herron has outlined how the adaptations are taking shape.
“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,” he shares. “All the big changes to plots have been made with either my happy agreement or, sometimes, at my suggestion.”
Herron is even keen for the adaptation to diverge from the source material, provided two important elements continue to be preserved. “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.”
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Changes to the source material, says Herron, will sit alongside scenes straight from his books. “There are scenes in Slow Horses, and in all the other ones that are coming up, which are matched pretty much beat-for-beat for scenes I wrote in the book. Then there are other scenes which are going to be different. It'll be a mish-mash, which is how it's always going to be.”
The Slough House series currently stands at eight books, but as yet Herron is unaware of any long term plans to develop the whole run, although he’d be “delighted” if there were. “I'm not privy to those kinds of conversations, to be honest,” he admits.
“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.”
As for Reconstruction and Nobody Walks, Herron’s novels linked to the Slough House universe which feature characters from the series, there’s no word if Slow Horses’ success will see them brought to screen in the near future. “There haven’t been discussions about filming them, but it certainly remains a possibility,” explains Herron. “For the time being, it's the Jackson Lamb series which is being focused upon."
Despite such focus on the characters and their new on-screen portrayals, Herron isn’t writing the characters differently due to the influence of the Slow Horses cast’s performances. “I'm not responding to the way the actors portray the characters in the way I'm thinking about the characters,” he reveals.
“On the other hand it wouldn't worry me if that did start to happen. The actors are doing so much work to embody those characters as they are on the page, it would be like taking part in a dialogue with them.”
In the case of Jackson Lamb, having Gary Oldman’s voice in his head won’t affect how he writes for him. “If I start writing dialogue for Jackson Lamb and thinking of Gary Oldman's voice while I'm writing, that's not going to make any difference to what I write because he is playing that role so consummately.
“It's not like he's bringing a huge set of other things to the role; he's playing Jackson Lamb the way he perceives Lamb to be on the page and in the scripts he's given.”
Slow Horses is available to watch on Apple TV+ – you can sign up to Apple TV Plus here. Meanwhile, Bad Actors, the latest Slough House book, is out now. Herron won this year’s Theakston Old Peculier Crime Novel of the Year for Slough House, one of the series which inspired the Apple TV+ Series.
Read more from Herron in the Radio Times magazine crime writers special, alongside interviews with Lynda La Plante, Val McDermid, ML Longworth and Michael Connelly.
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