"Nobody knows why I'm here, there's no deference," she says, before fine-tuning: "There's deference to me because of my age and because of my politeness."
The 67-year-old could not be less interested in fame.
"It's not good for people to be famous or perceived as such, or at least I've never known anyone who's been improved by the experience," Leon told AFP.
"All of this success stuff is to a large degree very ridiculous," she said. "Success is absolutely overrated."
So while trusted advisers seal deals for televised series of Leon's works in Germany, or for a cookbook of the exquisite meals she describes in passing without fail in every book, she prefers to be essentially anonymous in the city she has called home for nearly three decades.
"I'm like Louis XV, I'm in the hands of my advisers," she joked.
Leon and other expatriate writers have faced criticism for stereotyping Italy, Italians and in her case Venice.
"There's the risk of falling into stereotypes, and Leon, despite the bonhomie of her Commissario Brunetti, is not exempt. It's not for nothing that she doesn't want her books translated into Italian," wrote prominent Italian reviewer Ranieri Polese.
Leon responded with a touch of sarcasm: "You have no reason to believe this, but the only time an Italian (reader) has criticised them, it was one woman who read them in German and said I used cliches. Imagine that, in a crime book, of all places!"
She added: "Every other Italian who has read them has said they like them, remarked that they are surprised that someone who is not Italian can so well understand the place, has asked me to have them published so that other Italians can read them."
In Leon's novels, Brunetti's sleuthing takes the reader through Venice's unique labyrinth of alleyways, aboard vaporetti or police launches navigating the waterways and, more often than not, into the seamy side of local politics and business.
Morality, even for someone who professes to have been brought up on "religion lite", underpins Leon's plots.
"I'm interested in why people do things, and I'm fascinated by the way people justify things. I find that intriguing," she said.
"I am of the mind that even (serial killer) Ted Bundy thought that what he did was right, somewhere in his psyche. It's very difficult to have the courage to do bad things that you know are bad."
Leon, who formerly taught English literature -- hence the literary references scattered through her pages -- wrote her first Venice whodunnit "on a whim", she says.
An opera enthusiast, she found herself one day in the dressing room at the city's 18th-century opera house, La Fenice, "and I got the idea for a book," said Leon. "I just wanted to see if I could write a book. I really wasn't interested in publication."
Nagged by friends, Leon, who was in her late 40s at the time, submitted "Death at La Fenice" to a contest in Japan, and won.
She has never looked back, churning out one episode a year, delivering a new manuscript to her publisher Random House every March.
Describing herself as a "work machine", she said her parents gave her the "Puritan work ethic to an unhealthy degree" -- but, and here's the part she feels "lucky" about -- "they never gave me ambition".
Leon, who won the Macallon Silver Dagger for Fiction for "Friends in High Places" in 2000, claims to have no particular design for her novels.
"I really don't plan books at all," she said, before launching into a story about how the central character in "About Face" was based on a woman she noticed at the opera who had clearly had multiple facelifts.
"I was maybe 100 pages into a book and I saw this woman (who) had had so much work that she had become sort of monstrous," she said.
"When I went back to work on the book, this woman invaded the book, and I had to rewrite it to be about her, because the memory of this face, which I saw for just two seconds, if that, would not leave me in peace."
Similarly, Leon doesn't quite know where her next book is taking her, just that it will be about the meat industry.
Like most of her novels, it begins with a murder. "I killed him and began the book with his autopsy. So he's dead, and I've written 150 pages and I've just discovered who he is," she said. "And it's going to be that he was killed because of meat."
Another advantage of Leon's work ethic is that it keeps her at her desk during the hours of the day when it is best not to go out amid throngs of tourists -- a reality of the Renaissance city that is a recurrent lament by her novels' characters.
Venice is a "livable" city, "but it's a temporal thing," she said. "If you go out before 10 am or after eight in the evening you can avoid them, but at times of the year it's un-bear-able," she said, drawing out the word for emphasis.
While shunning celebrity status, Leon allowed that success has its benefits.
"The only really neat part about it is the freedom that it gives a person," she said.
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