The announcement this week from Hollywood that Tom Hanks will star in the film adaptation of Dan Brown's thriller The Da Vinci Code may have excited the book's millions of fans around the world. But in France, there was a collective sinking of hearts.
Tourists flock to the Louvre, scene of the murder in The Da Vinci Code
The English journalist stood outside the church of St Sulpice, her heart pounding.
It was dusk and if memory served her well, it was just 20m up the 200 steps into the darkened nave.
That number had been precisely counted by the church's medieval architect to chime in with the ritual of the pagan goddess once worshipped on this site until the elders of the Christian Church claimed it as their own.
Her footsteps echoed on the cold flagstones.
Inside, the elderly Frenchman who went by the name of Monsieur Michel Rouge would be waiting for her. She sensed it might be a difficult encounter.
Perhaps he alone could unravel the secrets of the dark arts practised by the American author Dan Brown. The man whose quest to write a bestseller had so angered the French that even now mysterious forces were gathering to denounce him.
She looked up at his face in the half shadow, illuminated only by the blue of Mary Magdalene's robe in the stained glass window looming above them.
Then she took a deep breath and asked..."So what exactly is it about The Da Vinci Code that's upset you so much in France?"
Fact or fiction?
Michel Rouge was silent as he weighed his words carefully. But the journalist could see what he was thinking.
The book places heavy emphasis on symbols and cryptography
Perhaps it was because Dan Brown was American, perhaps it was because his bestseller mixed fact and fiction so successfully that the Da Vinci tourists flocking to France took every word as Gospel truth - their naive gullibility irritating the rational, logical French.
In fact, Michel Rouge is a tour guide at the church that is used as the site of one of the key secrets of The Da Vinci Code, and one of its most brutal killings by Silas, the albino Opus Dei monk and murderer.
Except that Opus Dei, the Catholic organisation, does not have monks. Nor is it a sect. And St Sulpice does not hide the secret that Dan Brown describes.
Michel smiles as he explains that he does not actually mind, as long as the grail-hunting tourists are not abusive when he tells them that the book is not true.
Like 17 million other people across the globe, he has read The Da Vinci Code and enjoyed it.
But what worries him is the introduction, which claims that all descriptions of artwork, architecture and secret rituals are accurate.
Well, up to a point.
St Sulpice undoubtedly exists. But it is not the site of a Roman temple. Nor, Michel Rouge says, does the obelisk there hide a secret cave. Nor, indeed, is the obelisk Egyptian.
Author Dan Brown is a former school teacher
So fed up is the church with tourists asking to see where the fictional nun was murdered that it has put up notices to make it clear that while the church is real, the events in the book are not.
Some visitors, though, simply do not believe it... and they keep stealing the notice.
They tell Michel Rouge that he is covering up for the Catholic Church but that now, thanks to Dan Brown, they know the truth - that Jesus was married to Mary Magdalene and that they had children whose descendants became French kings.
Michel shrugs, and raises a sceptical eyebrow.
Despite everything, he says, he is glad more visitors are being drawn to the church, whatever their motives.
The Gallic shrug approach is also taken by Opus Dei, described in the novel as a rich, powerful and violent Catholic sect.
I speak to their press secretary Arnaud Gency on the phone, so I cannot tell whether he is an unusually large albino monk, nor if he is wearing a spiked belt around his thigh to mortify his flesh.
It does not sound like it though, as he laughs while discussing the impact of a book in which his employer is one of the main villains.
Arnaud read The Da Vinci Code, but admits that to him, its popularity remains its greatest mystery.
He directs me to the Opus Dei website for their wonderfully understated riposte: "We hope that Da Vinci Code readers interested in Christian history will be motivated to study the scholarship in the NON-FICTION section of the library."
And yet, in this secular age, what is it about a novel based on religion and sacred signs that has captured so many imaginations?
Arnaud Gency agrees that perhaps many readers are seeking a spiritual side to life, especially those who do not have - as he puts it - much historical knowledge or culture on which to base their beliefs. Americans, he means.
But how does he explain the book's popularity in France?
"When you read the book," he says, "you have the feeling that you are learning a lot, and the French love that. But when you realise that what Dan Brown writes is actually wrong, it is a bitter disappointment. At least in France..."
It was dark outside as the English journalist left the church... and for a brief moment, she thought she could hear voices.
"Dan Brown is publishing a sequel," they whispered.
"Oh no", she thought, and she could almost hear the groans of French agony resonating through the ancient paving stones.
From Our Own Correspondent was broadcast on Saturday, 4 December 2004 at 1130 GMT on BBC Radio 4. Please check the programme schedules for World Service transmission times.