He shook his head. “No, my proper office is in La Défense, not far from here.”

I was very familiar with La Défense, having done business there once, for a former job.

“But Wednesdays,” Luc went on, “I work from home. That’s why—”

“I have to wait right here,” I interrupted.

“OK.” Luc stopped with me on the pavement. Looked around. “Why?”

“I’m supposed to meet Denise.”

We were exactly at the place where I’d been told to be, in front of the château and right across the street from the old church with its grand steps and portico, now sheltering a scruffy group of youths who didn’t look at all religious. The traffic had grown busier.

Luc said, “I don’t think you are.”

“I am. She told me to be here at three o’clock.”

His answer was to hold his right hand up the way a person did when swearing on the Bible, so that I could see the ring of car keys dangling from his fingers. “That’s what she told me, as well.” He smiled and flipped the keys into his fist again and moved a step in front of me to take the lead. “Come on,” he said. “I’ll drive you home.”

I didn’t understand.

I said so. “I don’t understand. Why did Denise send you?”

I saw the lifting of his shoulders in the faint shrug that was such a quintessential French expression. “She couldn’t come herself. She’s gone to Chinon.”

“Where is that?”

“The Val de Loire. Her family’s there, and she and our son Noah always have their Christmas Eve in Chinon. Normally they come back the day after, but this year I was away as well, and so Denise left Noah with his grandparents to have a short vacation. She’s just gone to fetch him home.”

He’d had the luck to find a parking space a few steps round the corner in a street that ran beside the old château. He stopped beside a dark red Peugeot hatchback and unlocked the doors as I tried working through the logic of what he’d just told me.

It was possible, I knew, that I’d been told all this before—Denise could easily have talked about her plans to go to Chinon and, depending how absorbed I’d been in working on the cipher, I might not have paid attention. All she’d said this afternoon when she had come into my workroom was, “I’m leaving in a minute,” which could certainly imply that I was meant to know where she was going, and presumably the phone call she had made before we’d left had been to Luc, to make sure there’d be someone here to meet me.

“But,” I asked him, “why did she send you?”

He paused with a hand on the passenger door handle, turning to look at me. “Sorry, I’m not thinking. If it makes you too uncomfortable to drive with someone you don’t know—”

“It isn’t that.” I shook my head, deciding that it really wasn’t something I could easily explain to him. My cousin often said that men were clueless, and in this instance that seemed to be the case. If Luc thought it was normal for his ex-wife to arrange for him to meet me, clearly he had not shared my experience with couples who’d divorced. Even Jacqui, who’d be happy not to be in the same time zone as her exes, kept a faintly jealous eye on all their new associations, and she never would have volunteered them to chauffeur another woman.

Luc was waiting.

“Never mind,” I said. “It doesn’t matter.”

Usually, if I were honest, I did feel uncomfortable in cars I wasn’t used to, though this morning in Denise’s car I had been too distracted by her driving speed to notice. And as I settled now into the passenger seat of Luc’s car while he swung my door closed and walked round to his own, I felt a sense of the familiar that distracted me as well, until I put my finger on its cause.

“Is this a Peugeot 207?” I asked him as he slid behind the steering wheel.

“It is. An old one, though: 2009.”

That would explain things. I nodded and said, “Jacqui’s second ex-husband had one of these, only his was a coupe cabriolet, not a hatchback.”

“I wanted that one, too.” Luc smiled as he released the handbrake. “But Noah was still small and there was no place for his car seat.”

As we moved off from the curb I cast a glance into the back and saw a child’s booster seat. “How old is Noah now?”

“He’s nine years old. Nine and two-thirds, if you ask him.” He had seen what I was looking at. “When he turns ten he plans to set that booster seat on fire, I think. He knows it is the law for him to use it, but he hates it.”

So then Noah was a law-abiding rebel. Like his father, I decided, for although Luc drove with care he had a sure touch with the gear lever that made me think he would have much preferred an open road where he could shift into top gear straightaway instead of being trapped within these winding streets that slowed his speed.

He was wearing jeans again today. I liked his legs in jeans, though in the confines of the car their muscled length was stretched so close to mine I had to force my gaze elsewhere to keep from staring.

We were crossing the bridge now, and leaving the château behind.

“Does she have very many ex-husbands, your cousin?” he asked.

“Only two. They were both very difficult men.”

“This is why she is able to take on such difficult authors,” he guessed, “like this Alistair Scott. Denise tells me that he and Claudine have a history.”