When we got back to the flat, the sitting-room was almost dark. Aidan lit the gas lamps on the wall and blew out the match, his eyes on my face. I bustled about, unbuttoning my gloves and unclipping the fox’s tail from its mouth, taking off my hat and patting my hair. “My feet are freezing. Might I have a bath before I go?”

He went on looking at me, the spent match still in his hand. “Clara, you’re not going anywhere. Please, stop this silliness and listen to me, will you?”

“Silliness!” I was incensed. “Why am I being silly because I have refused to be party to pointless revenge? Why can you not admit defeat?”

He patted his pockets for cigarettes, retrieved a crumpled pack and searched it.

My patience broke. “And why must you smoke all the time?”

He found a cigarette and lit it, his eyes still on me. The smoke made a blue stalk in the air. “We all have our vices,” he said steadily. “And in answer to your other question, I cannot admit defeat because what I am proposing is not ‘pointless revenge’. It is an opportunity to do something that should have been done – I should have done – a long time ago.” He took a shaky breath, and his face took on a stubborn, determined look. “Clara, I must tell you that you are not the first to suffer at David Penn’s hands. But if you help me now, hopefully you will be the last.”

Illuminated from behind, Aidan’s features were almost invisible. And it seemed to me in that moment that everything else about him was invisible too. Who was this man? In the months we had worked together on the film, through all the scenes we had rehearsed and filmed, our physical proximity, our shared exhaustion, he had cultivated an air of cynicism, even arrogance, as if everyone else was a child and he an adult. He had behaved as if treating it all as a joke was the only way he could survive. Perhaps it was. His offer of future help, which I had not even understood at the time, remained the only chink in the door he kept so tightly closed.

As I stood there in my stockinged feet, coat and fur over my arm, my anger subsided. “Why do you care so much?” I asked softly. “If I end up being cited in a divorce case and am branded a … what did you call it? … a scarlet woman, then that does not affect you at all. If I do not agree with what you propose, what does that matter to you?”

He went to the window. The curtains were not yet drawn. He looked down to the street, but it was clear that he was not seeing it. After three or four puffs, he began to speak in a sort of distracted murmur, as if he were talking to himself.

“If I tell you what I know about David, you will understand. Did you know his real name is David Penhaligon?”

I thought of Mr Reynolds, my old schoolmaster, instructing us in English about the British Empire, and my da at home, using his mixture of Welsh and English to tell me about the British government’s attitude to Wales, the Welsh and our ancient language. Cornwall had an ancient language too, and “pen” meant “head” in both of them. I wondered, randomly, if David knew that.

“No, I didn’t.”

“They are a family of criminals,” said Aidan. “His father’s been in prison for years, and his mother went off with someone else. He started in films as a runner, a messenger boy, and because he’s good-looking he got taken up by a rich woman and taught manners. She gave him money to start his company. But then of course he dropped her as soon as he began to be successful.”

I tried to digest what he was saying. “But how do you know all this?”

“Because…” He sat down on the sofa and reached for the ashtray. “She was my mother.”