We asked Alen Mattich, financial journalist and author of the “The Heart of Hell,” 10 questions about the Marko della Torre series. Here’s what he had to say:

1. What can readers expect from Marko della Torre in The Heart of Hell?

In this third book of the series, della Torre finds himself ever a small wheel in the machinery of international politics and the brewing Yugoslav civil war. His superiors and American agents push him to track down his erstwhile colleague Julius Strumbić in the besieged city of Dubrovnik. But with Strumbić’s help he regains some autonomy and discovers why the U.S. government is so keen to track down an eliminate anyone who knows something about the Pilgrim file.

2. Where did the inspiration for the character of Marko della Torre come from?

When I started writing the first book, which ended up becoming Zagreb Cowboy, the main character was a KGB agent while the setting was Moscow. Around the same time I needed to go to Zagreb. It was January, the city was cold and atmospheric. Gas lanterns lit the deserted medieval old town while snow fell softly against its cobbled streets. Now and again, the silence would be broke by the sound of trams grinding through the newer, Habsburg part of town. No one had really written about Zagreb and I knew it well. Changing the setting meant that I had to change my protagonist. Croatia also had its version of the KGB, the UDBA. But I wanted to humanize, soften my protagonist. So I made him an internal investigator rather than one of UDBA’s thugs. I also wanted him to be something of an outsider, so I made him part ethnically Italian from the coast. As for his name, it’s a pun on the word dilatory. Because that’s the essence of his character.

3. Were there any challenges to writing a third installment in the Marko della Torre series (The Heart of Hell)?

There are always challenges to writing—not least keeping characters and situations interesting. But for the Heart of Hell, these challenges were exacerbated by the fact that I was under a severe time constraint. I didn’t help myself by losing my way in the first version of the manuscript. The narrative was wrong and the structure of the book didn’t work. My editor took a harsh but correct view that most of it had to be rewritten. And I did.

4. What’s next for Marko della Torre?

To be honest, I don’t know. I left the third book open enough that the character could be revived.

5. Do your experiences of in living in many countries— Libya, Canada, the United States, and now living in the U.K.—influence your writing or the characters you write about?

Maybe. Writers tend to like writing about outsiders. And having lived in many countries gives you—repeatedly—the experience of being an outsider.

6. Do you outline the plot and twists and turns of the book(s) before you begin writing, or begin writing and then see how your ideas develop and unfold as you go along?

Before I start writing, I usually have a sense of the beginning—the situation that initiates the action—and the main characters as well as two or three major plot points and where I want to end up. These can change. A plot point can be dropped and another one introduced. But when I start they represent markers, early goals. Then my job is to join it all together in a convincing and interesting narrative.

7. You currently write for Dow Jones and the Wall Street Journal. How did you go from “Financial Journalist” to “Thriller Writer”?

Some journalists are primarily reporters and have to build their story around concrete facts. In a sense, they’re accountants who build spreadsheets with words. But most journalists are firstly writers. I happen to be an economist by training, which is why I became a financial journalist. But most financial journalists haven’t got the same background. They write about whatever it is that is presented to them or catches their eye. I think I’m that sort of writer. So moving from journalism to thrillers—or children’s books or romantic fiction or any other sort of story telling—isn’t a leap. The only trick is to find the time and energy to write other stuff as well as what you’re meant to be doing as your day job.

8. What are the elements needed for a truly great thriller novel?

Most of the ingredients necessary for a great thriller novel are the same for any good piece of fiction: convincing characters, a strong narrative, situations and circumstances presented in an interesting way—even if they’re routine. Thrillers tend to put more weight on narrative, on heightened circumstances where the danger is usually physical rather than just psychological. But good books all have broadly the same high quality ingredients, even if they’re in differing proportions.

9. Who are your three favorite thriller writers?

I’m not sure I really think of writers by genre. But the ones who have written thrillers I’ve liked are Alan Furst, Elmore Leonard, Robert Harris.

10. What are you reading right now?

Right now I’m reading Warsaw 1944, a rather grueling history of the Warsaw uprising and the city’s destruction by the Nazis. In terms of fiction, I recently finished the first of Mary Renault’s trilogy about the life and legacy of Alexander the Great, Fire from Heaven, both because they’d been recommended to me by my eldest daughter. I’m also finishing up Varlam Shalamov’s Kolyma Tales, a group of stories about life in a Siberian Gulag.

The third installment in Alen Mattich’s highly addictive Marko della Torre series.

Autumn 1991. Civil war has broken out in Yugoslavia with Croatia’s declaration of independence, and former secret policeman Marko della Torre is set adrift. Department VI, the internal investigations unit, is now in a state of paralysis as Belgrade struggles to maintain its hold as the region’s centre of power. When the body of a young woman, identified as American agent Rebecca Vees, washes up on the shores of Italy, della Torre is summoned by U.S. authorities. He is the last person to have seen Rebecca alive. Her two colleagues have also been found shot dead on an island in Croatia, and della Torre is coerced into locating the man they think is responsible: the corrupt and unscrupulous Zagreb cop, Julius Strumbić. Forced to navigate Yugoslavia’s bloody civil war in order to track Strumbić’s whereabouts, della Torre has to decide whether he will warn his old friend or give him up to the Americans to save himself.

In The Heart of Hell, Alen Mattich delivers a powerful political thriller that depicts the horrors and machinations of the Yugoslav civil war and the humanity of those who survive it.