Dead Lions, the second in your Slough House series, appears to be a big departure from your earlier books.

It didn’t feel like so much of a departure at the time, though I was conscious of wanting to write about a group of characters, rather than concentrating on a single viewpoint. Making them failed spies had a peculiar appeal; it would make them resentful, eager for redemption, and prone to bad behavior in equal measure.

Talk a bit about Jackson Lamb, your somewhat despicable protagonist.

Well, I wouldn’t want to work for him myself, but he’s fun to write. Lamb is less despicable than conflicted. A spy out of time. In his undercover days in what was then the Eastern Bloc, he was brave and resourceful—which he might still be, if he can be bothered. But as the end of Slow Horses [the previous book] makes clear, his voluntary exile in Slough House was triggered by disgust, with both the system and himself. Lamb comes on like a despot, but he can be ferociously protective when outside forces threaten his crew.

Russia seems to figure in spy fiction today as much as it did during the Cold War, and you address terrorist threats and corporate intrigue.

Russia looms large in Dead Lions because the central characters are Cold War veterans, refighting old battles. Terrorism has always been around in one form or another: the difference between a sarin attack on a subway and a blanket laced with smallpox is one of technology, and while corporate and financial intrigue make up many of today’s headlines, the underlying stories could be written about the East India Company and the South Sea Bubble. The fundamental things apply...

How have readers responded to the comic element in Dead Lions and Slow Horses?

The humor mostly comes from the characters’ interactions, and from the narrator’s cynical viewpoint—which isn’t necessarily my own, or not always. I regard both books as thrillers, but I’d hate to write anything that didn’t have a discernible sense of humor.

Where or how do you learn enough about spycraft to write about it with authority?

When imagining how an intelligence service might operate, I simply bear in mind that the corporate mindset is naturally Machiavellian, then aim for an extra layer or two of deviousness. As for spycraft, John le Carré showed that spying, like every profession, has its own language. The more confidently you use it, the more authority you appear to have.

What’s next?

The Slough House crew will be back.