What made you want to write Endgame?

I always planned to write a series of three or more books. As well as coming up with a smart-ish spy plot and climax for the third book, I also wanted to provide some closure in relation to the hero Daniel Ambler and his relationship with his ex-wife, Sara. I wanted our Catholic hero to find a little redemption.

Can you tell us a bit about Daniel Ambler in this novel, and what sets him apart from other spy protagonists?

In some ways he is not too far apart from other protagonists in spy fiction. He is named Ambler as a nod to Eric Ambler, who featured “ordinary” heroes thrust into extraordinary circumstances in his books. He drinks as much as the next spy – and is as faithful to women to boot. Readers and other writers may find Ambler of interest as he is a spy (often a reluctant one) who is also a spy novelist. The character gives us a window into the world of publishing, as well as espionage. The first book in the series, Duty Calls, was partly inspired by The Russia House, by le Carre, which also mashed the two worlds together. Ambler may be considered barely heroic, though – which is why James Marshal, a former soldier, features in the story. From the outset I wanted to write some books which were a blend of Jack Reacher and Graham Greene, if you can believe that. If Ambler provides the kiss kiss, Marshal delivers the bang bang.

Your novels are known for their humour. How do you balance comedy with danger when the stakes are high?

The comedy and satire are a compliment to the spy thriller elements in the novels, not the focus. Both Marshal and Ambler can be glib and sarcastic, even when in danger or when comedy is not always called for. Some readers may even be offended by some of the jokes in the novels, but those are also the ones which may make others laugh the most. Gallows humour may be the death of me. Thankfully, Ambler has the capacity to laugh at himself, as well as others. There are also a few in-jokes related to being a writer, which my author friends enjoy.

The plot hinges on secrecy and undercover work. How do you build tension while keeping the story moving at speed?

Pace is of paramount importance, but there needs to be breadcrumbs of intrigue and peril sprinkled into the recipe too. Whether it’s because Ambler is an author or not, he is seldom lost for words. He’s adept at lying, which is not to say he is proud of how good an operative he ends up being. In some ways he is a lucky spy too, but everyone’s luck runs out sooner or later.

Which crime or spy novelist inspires you most when you sit down to write?

These novels wouldn’t exist, I warrant, without the influence of Graham Greene and John le Carre. I tend to re-read them whenever writing spy fiction. As well as being strong on plot and character, there’s a sly humour to them both which is not always appreciated. I also enjoy reading Alan Judd, who is another craftsman who seldom wastes a paragraph. I’ve enjoyed most of the Slough House novels by Mick Herron, though I think I enjoy the TV series even more due to Gary Oldman’s portrayal of Jackson Lamb.

You clearly enjoy writing twists. How do you test whether a twist is truly unpredictable, and when do you know it’s working?

I actually come up with the dénouement first, before plotting anything else in earnest. Crime and spy novels need entertaining, but credible, payoffs. Most readers know by now that there will be some kind of twist or reveal at the end of my spy novels, which is partly why I plant red herrings into the story. Whenever I have a reader come back to me after finishing a book I always ask if the twist worked – and if they guessed it. Thankfully, most don’t see things coming.

Can readers expect more from Daniel Ambler after Endgame?

I’m not sure yet. In the same way that James Marshal made a cameo appearance in Endgame, Daniel Ambler is going to feature in the next James Marshal book, Time To Kill, which will be out by June 2026. Endgame would imply that it is the last book in the series, would it not? But you should trust an author about as much as you should trust a spy.

Thomas Waugh is the author of the Daniel Ambler Spy Thrillers and the James Marshal Thrillers.