“So the first thing you should know,” said Marguerite, trying to take a pastry without looking and knocking over the salt instead, “is that I am very, very, very sorry about pointing a gun at you. I thought somebody dangerous was on to me, and possibly armed themselves; I never thought for the smallest second that it would be you. And between you and me, it isn’t loaded.” She successfully located a kakaós csiga, a “chocolate snail”, and took a bite. “Generally,” she said through her mouthful, “I find that you can have the same effect just waving the thing around and using a bit of cunning.”

“But why do you need—”

“Getting to that!” Marguerite waved her csiga about in agitation. “We don’t have much time, mon lapin, I must say all the important bits quickly. And you must listen just as quickly: ready?”

Max folded her arms and leaned back, to show that she wasn’t anybody’s lapin yet. But she nodded.

“Number one –” Marguerite held up one finger “– I am not the thief. Number two –” two fingers “– the thief is certainly travelling with us by train. And to explain how I know that, I should begin by telling you thing number three…” Three fingers, and then her hand dived back into her habit, and she produced a battered leather wallet. “Before I was a nun, Max, I was a commandant. And a much better one than that idiot Le Goff. I specialized in the international black market for diamonds and jewels.”

Max picked up the wallet, and opened it. A younger Marguerite stared out, dressed in a shirt and with her hair scraped into a skew-whiff bun. The word POLICE was stamped below her in red, along with a lot of small print, and there was a shiny silver badge on the other half of the wallet. Max studied it suspiciously. It looked real.

“I wanted to carry on,” sighed Marguerite. “But the police said they couldn’t have a nun for a commandant, and the convent weren’t too keen on having a commandant for a nun. I had to choose, so officially, I’ve given it up.”

“And unofficially?” said Max. She looked from the policewoman to the nun, and back again. The same kink in the nose, the same amused twist to the mouth.