Kate didn’t answer.

He took her silence as leave to continue. ‘All right. This chap Sergei was a friend from your time as a student in St Petersburg, correct?’

‘It’s in the file.’

‘He ended up in London and it was clear to you he was working for one of the Russian intelligence agencies?’

‘Yes.’

‘And his previous assignment had been in Istanbul, so when he told you these intelligence chiefs were in the habit of gathering on Igor Borodin’s super-yacht in the summer there, you thought the information credible and the yacht a sensible target for a bugging operation.’

She nodded curtly. What intelligence officer wouldn’t? Where was this going?

‘But Sergei was your only source?’

She glanced at Grove. ‘Yes.’

‘Who knew of your prior friendship with him? I mean, within MI6?’

Kate shook her head. She couldn’t see the relevance of the question. ‘Anyone on the top floor would have had access to my vetting files. It’s in there somewhere. We have to declare any significant friendships prior to joining the Service, and I did so.’

The prime minister glanced at Shirley Grove, who had aged visibly since Kate had last seen her. The lines around her eyes were thick with accumulated fatigue. She gripped her reading glasses in her right fist, as if about to use them as a weapon.

‘Did it occur to you at the time that the tip-off might have been too good to be true?’

‘I admitted to the—’

‘I’m not interested in some crap inquiry.’ He leant forward. His anger matched hers, and even in the low light, his eyes were a deep, vivid blue. She had the briefest sense of why so many women lost their heads over him. ‘I travelled all the way down here to find out what you really think.’

She held his gaze for a moment more. Was this some kind of trap? ‘Yes, it occurred to me that the tip-off was convenient, if that’s what you’re asking, but I trusted Sergei. I’d known him a long time. I didn’t think he’d lie to me.’

‘You bug the yacht and it delivers the bombshell. But you lack hard proof of my treachery. So when you’re later told that a Russian defector has all the hard evidence to prove your theory, of course you’d jump at it. And the video of me “having sex” with underage girls in Kosovo looked entirely authentic and convincing.’

‘I was certain it was you in the footage, yes.’

The PM didn’t flinch, his gaze still locked on her. ‘I’ll tell you something, Kate. I may be many things, but I am not a paedophile. Nor have I ever paid a woman of any age for sex.’ The hint of that familiar smirk suggested he still believed he didn’t need to, but Kate didn’t allow herself to react.

At last the waiter brought the wine, uncorked the bottle and poured. Only the PM reached for his glass.

‘All right,’ Kate said, wanting to be away from there now. ‘I’ve been through this over and over again. I gave Mrs Grove everything she wanted and needed when I left MI6. I admitted I’d been set up, used, hoodwinked, fooled – pick whichever term you like. You were completely cleared. I left in effective disgrace. And the quid pro quo was that I’d be allowed to get on with my life.’