In The Garden of Evil you have to write about modern forensics, painting, and the Medicis.  How did you do your research?  Was it fun?

I'm a research junkie and if I could spend ten years on each book I would. For Garden I spent most of one winter inside palaces and art galleries, and reading some hefty academic works on Caravaggio, the Rome of the early 17th century, and the lineage of the Medicis. The science side of things comes from contacts and the web; the worm convention mentioned in the worm autopsy scene is a real event, by the way. Sometimes truth really is fiction. I adore and have to stop myself doing more.

I live near San Francisco where the oldest buildings go back two centuries or so.  What's it like setting a book in Rome where structures from two millennia ago still stand?  How does Rome's status as the Eternal City affect what you write?

I've spent so much time in Rome over the last eight years I've become part Roman in the sense that I tend to take it for granted. Sometimes I have to pinch myself when, for example, I saw a bouquet of flowers in the forum and think... oh yeah, that's where they burned the body of Caesar. I picked Rome for a number of reasons. I like the place because it's real, not a tourist invention. No one else seemed to write anything there. And, more than anything, it's a city that stands for something, even for people who've never set foot in Italy. It speaks of a society looking for order, justice and freedom, and usually finding very little of these things. That seemed to me to reflect very well on the world of today.

Two other British authors of mysteries set in Italy, Michael Dibdin and Magdalen Nabb, died last year.  What made them as good as they were and how do you think their books compare yours?

I never met Dibdin but I did meet Magdalen, who was quite a character and basically took over a book event for me in Florence a few years ago. Didbin was a very literary writer who tried to see Italy from the inside (he worked there as a teacher). Magdalen was more on the cosy side with her tales of a friendly maresciallo in the Carabinieri in Italy. To be honest I think their work is a long way from mine. They carved out their own fields, pitching stories in Italy at a time when it was quite unfashionable to set stories abroad - which was very brave of them. While I spent a lot of time in Italy planning these books and studied at language college, I feel I write with very much an outside eye, of international events usually, in a very international city. Oddly enough my Italian publisher doesn't see them that way at all but says they come across as Italian books. So what does an author know about anything?

You left secondary school and went straight into a journalism job.  Did that give you a leg up over other writers who endured four years at university and maybe more doing a Master of Fine Arts in Creative Writing?

I was too poor and too dumb to do college and didn't even finish secondary school because at the age of seventeen I was offered a job as a cub reporter on a little local newspaper. I adored journalism and it was very kind to me. I never went abroad until I was 21 but working for the London Times sent me all over the globe over the next few years. I think that developed some useful skills: observation, editing, a complete lack of fear of the page. But journalism gives you bad habits too, principally an unhealthy (in fiction terms) obsession with telling things the way they are. Fiction is a polite word for lies, and they get you fired as a reporter. I'd love to go to college some day though - but I doubt it's going to happen.

Poor fellow.  You spend time in Rome every year, don't you?  Where do you stay?  What do you do?  What do you like about the city?  How does it compare to London or New York?

I spend a lot of time in Italy writing, thinking and researching. Usually I rent apartments for a few weeks at a time. I don't want to own anything there (I don't like the way second home owning-foreigners are pricing out the locals for one thing) and I like to stay in different areas. My favourite in Rome is the working class suburb of Testaccio which is still truly Roman and home to lots of friendly communists. Having lived in London I am qualified to say the place is a dump. New York is beautiful to me but nothing compares to Rome, which is essentially a bunch of urban villages attached to each other, all with their individual characters and foibles.

Do English and American thriller writers see the world differently?  How so?

I'm the wrong person to ask. American writers have probably influenced me as much if not more than English ones. I love the American focus on movement, characterisation and brevity. We Brits can be a bit too wordy for our own good too (and I include myself in that sometimes). I want my work to be three things: popular, intelligent and original. I suspect there are a few Brits who think the popular part is unnecessary, which seems a touch snobbish to me. But fundamentally I don't think we're different at heart; we're all trying to tell tales that strike a chord with the ordinary reader.

Lots of writers started writing a series and then broke out with a standalone.  You seem to have done things vice versa.  Any thoughts?

I wasn't ready to write a series when I started. I didn't know enough about characterisation, or appreciate how much hard graft was needed to see things through. If I'd started with a serial - and I was offered the chance to make my first book a series, set in Spain  - I doubt I'd be published now. This is a long game for most of us - which I quite like actually. Instant success usually leads very quickly to instant failure.

Any interest from Hollywood in the Nic Costa books?

Periodic interest and then they meet me and I tell them the story of how someone made a movie of my first book, Semana Santa (Angel of Death in America). I'm not ruling it out but I'd much rather see a TV series tackling the series of books as a whole rather than pulling a single title out and transforming it into something else entirely.

What's next for you and Nic?

My schedule's been brought forward for next year so you will see book seven in April in the US. It's called Dante's Numbers and for the first time ever the crew get on a plane. So it starts in Rome, based around a very noisy and controversial movie project, and then shifts very rapidly to the San Francisco area for the rest of the book. It's quite an unusual story for me, since, as the title suggests, it involves history, but not necessarily the history you think, and it also covers one of the oldest buildings in San Francisco you may be interested to hear. After that the team come back to Rome for a very political story set in and around the Quirinale Palace, home to the president of Italy (who is not, as he keeps reminding people in the book, the same as the US president).  

Indulge me for a final question, please.  You're from Yorkshire and had your first job in Scarborough.  What the heck were Simon and Garfunkel singing about when they asked "Are you going to Scarborough Fair" in their  "Parsley, Sage, Rosemary, and Thyme?"

I worked in Scarborough on the local paper when I was 17. For me then Scarborough Fair meant an annual carnival with vertiginous rides in which drunken Yorkshire youths indulged in projectile vomiting after a copious amounts of beer (not me -  I could handle the beer, but not the rides). Quite what parsley, sage, rosemary and thyme meant to us then I can't tell you however, because anyone who even thought of singing it was liable to be beaten up on the instant, on the grounds of being a wuss. It may still be that way for all I know. I would advise against Paul Simon and Art Garfunkel visiting to discover. And as for 'Bright Eyes'...

Contributing editor Keith Raffel wrote DOT DEAD, "without question the most impressive mystery debut of the year" according to Bookreporter.com. Former counsel to the Senate Intelligence Committee, he is currently finishing up TWO GRAVES, a political thriller set - where else? - in Washington, D.C.