Kate mouthed a silent curse as they all absorbed the brutal reality of this. ‘You want me to talk to our friends in the police?’ Yusuf asked.

Kate didn’t answer. Inform the police and everyone in Istanbul would know what had happened and would be asking why, not least Yusuf’s SIS superiors in London. Any chance at discretion and secrecy would be blown. But if the Russians were on to Demidova, they knew what was going on. And if they were aware, then Dante would soon know in London, too.

Her cover, such as it was, had been blown already. ‘Yes,’ she said simply.

Julie burned on to the highway bound for the airport. Within a few seconds, the battered old Citroën they had hot-wired was pushing through the 150 k.p.h. mark.

At the other end of the phone line, they could hear Yusuf talking to someone in Turkish. Halfway through, he broke off, and said to Zehra, in English, for Kate’s benefit: ‘Get going.’

He finished his conversation in Turkish, before offering Kate an explanation. ‘Our Russian friends have bought cover with the police. Must have cost them a fortune. Who knew this Demidova was so valuable? I have told Zehra to take the boys and see what she can do. It will be close and we can’t afford a shoot-out, but I will talk to our friends in MIT, see what can be done.’

‘Thank you, Yusuf, as always.’

‘I will have some explaining to do with your friend Mr Ian Granger if he gets to hear of this, but such is life. I could speak to someone in the prime minister’s office here. Perhaps if—’

‘No, it’s all right.’ Kate was aware how much political capital Yusuf was offering to expend and she was touched, but that would create an enormous crisis within SIS back at home, which would blow the last chance of shielding this from Ian and his colleagues.

Julie kept her foot on the accelerator as the minutes crawled by, and Yusuf calmly announced the Russian team’s advance on the airport. ‘This is crazy,’ Julie said, after a while. ‘What are we going to do? Try to bar the approach to the plane? They’ll just shoot us and get on board.’

‘I doubt their police cover involves a murder charge.’

‘Maybe that just costs extra.’

They could hear the calls Yusuf was making in Turkish. It was probably ten minutes before he came back to them. ‘MIT say they will look into this, but if the police decide to block the arteries of action, I don’t think I can get there in time unless I go to the prime minister’s office.’ There was another silence. ‘You are four or five miles behind them, so if they have a wave-through, I don’t see how you can interdict.’

Julie asked Callum to navigate them to the entrance to the private terminal, but Kate knew they were counting down to failure now. Yusuf called out the progress in his steady, lugubrious way. The Russians were six minutes from zero, Kate’s team twelve or more and Zehra and ‘the boys’ around the same. Neither could close in on the Russians.