‘I wouldn’t know that sort of thing. You’d have to pop into our gallery on Charlotte Street and—’

‘Is someone there now, one of your colleagues?’ I wasn’t going to let it drop. She was lying to me, and I would force her to admit it. ‘You could ring and ask them. Tell them you’re with someone who’s keen to buy any painting you’ve got by Mary Trelease, as long as it’s signed, dated and recent.’

‘There’s no one there who’d . . . Look, I’m not . . .’ She was getting flustered. She spread both her hands and lowered them slowly in a calming gesture. ‘To be honest, I don’t think we’ve got any other stuff by her, okay?’

‘Do you represent her or don’t you?’

‘I’m not going to discuss details of the gallery’s relationship with a particular artist . . .’

‘An artist who refuses to sell any of her work,’ I snapped. ‘I’m right, aren’t I? Mary Trelease sells her paintings to nobody. Why not?’ I was certain my hunch was correct. Mary often used to bring in pictures for Saul to frame, ignoring me as she walked past me time after time, yet he never put her work up in the gallery. Saul always exhibited paintings by the artists he framed for; he used to tell me all the time that it was the best way to advertise his own work as well as theirs. So why not Mary’s?

‘I don’t know what you’re talking about,’ said the woman. ‘All I know is, we’ve sold one picture for her. This one.’ She jabbed her thumb at Abberton. ‘There’s nothing I can do about it. I can’t un-sell it. I’d be happy to sell you any of the other stuff you can see here. Everything else is available.’

I shook my head. ‘If Abberton’s sold then whoever bought it will be back here to collect it, won’t they? Did they say when?’ An art fair wasn’t like a gallery exhibition, Aidan had told me the day before. You didn’t have to wait until it finished to collect your purchases—you could pick them up any time before the end of the last day.

I got no answer, so I kept pushing. ‘Are they coming to collect it? Or did they pay extra to have it delivered to their home? Can you check that for me, on the yellow form?’

‘No, I can’t. Even if I knew, I couldn’t . . . Look, I really don’t see how I can help you any more. I hope I’m not going to have to call security.’

This shocked me, the idea that someone could feel threatened by me. ‘I’ll go,’ I said. ‘Just . . . could you do me one favour?’

She eyed me suspiciously, waiting for the worst.