Listen, listen, listen.

‘For the first time in my life, I’ve decided to do what William would call the decent thing.’

If she bursts into tears, William had added, don’t fall for it.

She burst into tears.

Beth thawed. ‘The gallery will never forget the invaluable role you played in securing the Rembrandt, a Rubens and a Vermeer, for which we will be forever in your debt.’

‘You will never be in my debt,’ said Christina. ‘But I must warn you that if Miles is ever arrested and sent back to jail, Booth Watson has been instructed to claim the Vermeer back, and there’d be nothing I could do about it.’

For the first time Beth thought Christina might be telling the truth, but she continued to listen, listen, listen.

‘Believe me, I’m determined to prove to you and William whose side I’m on. If there’s anything I can do to prove …’

The moment she pretends to be on your side and asks what she can do to prove it, is when you strike. Start with something small, William had suggested, and if she grants your request, you can then tempt her with something she won’t be able to resist. Just before she leaves, ask her one final question that will reveal if she’s telling you the truth, or is nothing more than a messenger carrying out her paymaster’s orders.

‘What a kind offer,’ said Beth. ‘The museum is hoping to mount a Frans Hals exhibition next autumn. I know you have The Flute Player in your collection, and we’d love to borrow it for six weeks.’

If she turns down your request, William had said, she’s admitting that Miles still has control of the entire collection, and that’s not something she’ll want you to know, as it leaves her with no bargaining position.

Christina hesitated. ‘I’m sure that will be fine.’

‘Thank you,’ said Beth, before casting a far bigger fly on the water. ‘That will compensate for the gallery not being able to afford Caravaggio’s Fishers of Men, which we were recently offered, but couldn’t meet the asking price.’ Word-perfect.

‘Is that public knowledge?’ asked Christina, rising to the bait.

‘No, it isn’t,’ said Beth. ‘Lord McLaren approached us privately. It seems that following his father’s untimely death, he’s experiencing an inheritance problem and the tax man expects him to come up with twenty million by the end of the year. I had to tell him that sum was out of our league.’ She paused for a moment, enjoying herself. ‘That’s confidential, of course.’

‘Of course,’ said Christina. ‘But at least I can help you with the Frans Hals. That should prove which side I’m on,’ she added, as she rose from her seat.

‘You have nothing to prove,’ said Beth, giving her a warm smile. ‘But may I ask you one more thing before you leave?’

‘Anything,’ said Christina.

‘Where is Miles at the moment?’

Christina didn’t reply immediately, but eventually murmured, ‘Buenos Aires,’ as if reluctantly revealing a well-kept secret.