‘My father’s family was originally from Georgia, as I am sure you know. We still have a home in Tbilisi and another in Kazbegi, just over the border. He thinks he can get himself, my wife and son there. So that is where we will meet. The Russians have the commercial airport covered, so you will need a private plane on standby to come in and pick us up – or, better still, to remain on the ground until we are ready.’

‘When?’

‘This week. You can send me the letter from your foreign secretary tonight – tomorrow at the latest. I will find a way to show it to my father. You will need to unfreeze the assets you have seized in the UK, including the house in Knightsbridge, where we will have to live. The letter will need to confirm we are free to move around as we please in both Europe and America.’

‘As you know, that’s not in our gift.’

‘You can deliver it. We will come with this video and incontrovertible evidence of the money we have paid to your prime minister over the course of the time he has worked for us – more than thirty million pounds in all – along with a global paper trail, which will allow you to seize the cash and arrest those who have helped launder it.’

They looked at each other. ‘All right,’ Kate said. ‘You very much have a deal.’

Mikhail forced a smile. ‘And hang the consequences.’

He picked up his bag and slung it over his shoulder. ‘You’ll be the most famous British MI6 officer since Kim Philby.’

‘Just what I always wanted.’

He walked to the door. ‘Sorry to have caught you off guard.’

‘There is one other thing.’

He turned back to face her. ‘You’re getting more than enough for your money.’

‘This concerns both of us. Is it true that my husband Stuart was the agent codenamed Viper?’

A flicker of alarm crossed Mikhail’s handsome face, all the more noticeable for the speed with which he tried to hide it. ‘What do you mean?’

‘Are you sure Stuart was Viper?’

‘Yes. Why?’ He was looking her in the eye now. Perhaps with a little too much intensity, as if he was determined to hide the momentary flash of alarm she’d witnessed a few seconds earlier.

Kate leant back against the desk. ‘Well, since you murdered my old deputy I was forced to acquire a new one, and she has some questions about our original operation that I’m having to admit I struggle to answer.’

‘Such as?’

‘Stuart didn’t know anything about Rav’s trip to Geneva.’

‘So . . .’

‘And Rav was much too smart to have drawn attention to himself while he was there.’

Mikhail shrugged. ‘If I recall correctly, he went to see the lawyer François Binot. Maybe one of my colleagues had him under surveillance.’

‘Why? Binot worked for you.’