I heard a crunching thud – the fall of a chunk of concrete. “Open the jar,” Bella said, and moments later “Wipe my hands for me.” I strained to hear more, but when neither of them had spoken for at least a minute I inched around the column. They had their backs to me and were already on the road.

As I followed, using pillars for concealment, I saw a jagged lump of concrete lying beside the rickety cruciform construction. It was at least two feet across at its widest point, and dauntingly thick. I would have needed both hands and a considerable effort to lift it, and how would I have dislodged it with my bare hands in the first place? I was staring at the patch of earth it had exposed, a handful of which had been scooped up – I was imagining how many insects it might have roused to scramble back into the soil, a thought that produced the unwelcome illusion that the faces on the columns all around me had begun in some way to swarm as though they were about to hatch – when I heard Roy say “That’s never…”

I felt robbed of breath until he spoke again. “It fucking is. It’s my dad’s fucking car.”

Julia and I had seldom heard him use such language, and I had a sense of encountering an aspect of him I was unaware of. What others should we know about? “Where are you, dad?” he was shouting like somebody more savage than I recognised. “We know you’re here.”

There was no point in hiding further, and I was glad to leave the blurred voice of the motorway behind along with the graffiti, even if a glance reassured me that the reiterations of a face didn’t appear to have stirred. As I emerged under the ramp Roy folded his arms, not by any means unlike a parent preparing to deliver a reproof, while Bella crossed her hands on her breasts, a gesture that looked placatory and yet oddly secretive. Roy didn’t speak until I was almost within arm’s length, alongside the car. “What do you think you’re doing, dad?”

He might have inherited Julia’s weariness with my behaviour. “Something like you are,” I said.

“I don’t see where you’ve got a specimen.”

“Not that. Just exploring, the way we did before, forgive me, before you met Bella.”

“So why are you still doing it?”

I aimed my question at them both. “Is there any reason you wouldn’t want me to?”

“We said we didn’t need a lift.”

“I don’t believe I gave you one.”

As Roy looked tricked rather than defeated Bella said “Patrick learned where the places were before you did. He had Thelma’s journal.”

“He didn’t have to come to this one now. He only knew we were because you told him.”