Why did he do it? Was he trying to make amends for something, to make good a debt? Was it a political gesture? Could it have been all of the above?

And that wasn’t all. Here you have a Catholic girl from Brittany, and supposedly a poverty-stricken one at that, who travelled a great distance from home to earn a living, who opened up a restaurant by the name of The Greedy Seagull the same year as the birth of her bastard son . . . What money would she have had to invest in such a business, which was, if one were to believe the postcard Granny Soize showed me, quite a decent size? And finally, why did she feature on my grandfather’s birth certificate as a farmer and not as a maid?

In that photo, which was dated 1875, Corentine appeared dressed to the same high standards as she was fifty years later in the portrait adorning her family vault: that is, impeccably styled and cinched into her stays. Even at that young age, she had the air of a triumphant businesswoman. It was hard to imagine her ever being in somebody else’s service.

The explanations provided to me by my family made the whole story seem like a jigsaw puzzle whose pieces had been jammed in with a hammer: it made no sense. My head, or rather, my imagination, craved more. I told myself it was far from a coincidence that those Parisians had come to drown their teddy bears on our island in memory of a de Rigny; it was like some sort of unacknowledged truth that had simply been biding its time before exploding . . .

In the train on the way home, thanks to the Mormon website familysearch.com, which has been relentlessly scanning parish registers from around the world since the 1960s in order to baptise the dead, I was able to reconstitute the de Rigny family tree in exchange for a few euros and a couple of clicks.