‘With respect, I’ve known Julie a very long time, and we’ve been through a lot of dicey days together. You’re young, new and very wet behind the ears.’

‘I never had you for the patronizing kind, but fair enough. My observation still stands, though.’

Julie swilled the remains of her drink around the bottom of her glass, then gave him the laser treatment with her eyes.

‘Please just give us a minute,’ Kate said.

‘No. I need to be in on it. Those are my instructions.’

‘And these are mine.’

‘I’m asking you to trust me.’

The distant hum of traffic and the whisper of the breeze off the Bosphorus made their presence felt in the silence that followed. Perhaps Callum was, Kate reflected, as tough as he looked. It might come in handy.

‘I think we do trust him,’ Julie eventually said.

Kate nodded. ‘All right. But you should be warned, knowledge and trust haven’t turned out to be of much value in this business to date.’

‘You mean for your career?’

‘I mean for my friend Rav, who was murdered in his apartment. I mean for my old friend Sergei, whose throat was cut on that train between St Petersburg and Moscow. I mean for my marriage, which is smashed to smithereens. You want me to go on?’

‘No, I understand.’

‘All right, we’ll trust you,’ Julie said. ‘But you’d better make sure you don’t betray that, or I’ll put a bullet in you myself. Understood?’

‘Completely.’

Kate leant back and gestured at Julie. ‘All right, shoot.’

‘Despite her taste for occasional Sapphic encounters,’ Julie said, ‘I’d say Tess was pretty straight. But we come back to the same thing. Isn’t it all a bit convenient? The prime minister needs to be cleared of suspicion and here, hey presto, is the means of doing it.’

‘Possibly, yes.’

‘We should still try to track Natasha Demidova down. I don’t see how we can really assess her until we can see the whites of her eyes.’

‘Let’s start at the tennis club tomorrow morning. Callum, could you hire a car and make sure you’re back at the hotel for breakfast at seven? We’ll go from there.’

Kate could tell Julie had more to say. ‘Go on, spit it out,’ she said.

‘There’s something else you should know, which I’ve been toying with telling you. Andrew has a new asset in Moscow.’Andrew Blake was SIS’s undeclared station chief, working undercover as head of Chancery. ‘He – or she – is codenamed Incisor, and came online about two months ago.’

‘Just after I left.’

‘Yes. Ian’s all over it like a rash, of course, but Andrew’s in the driver’s seat right now, and will be until he heads back to London at Christmas. Incisor’s intel has been pretty good so far, the main revelation being that Igor Borodin never entirely retired from the Service and continues to run some kind of special unit. Incisor arranges travel for its operatives and occasionally picks up gossip that way.’