She went backwards again to the original operation to get Lena and the electronic bug on to the yacht in Istanbul. She stared at the screen. It had long troubled her that the Empress had departed her buoy close to the Kempinski Hotel in the middle of the night. Why would the captain have done that, unless they had been alerted to something amiss?

She pulled up the phone logs, which Suzy had attached, and tracked her own movements. After returning from Istanbul, she had entered the SIS building that day at 15.58. She had gone straight to the meeting with Ian and Sir Alan. There had been plenty of time in the course of the evening for someone to have alerted Moscow.

Kate stared out of the window into the darkness. Did she actually believe Stuart, or did she just want to believe him?

She went back to the file and continued scrolling through it. She read the coroner’s report on Rav’s death. Verdict: suicide.

There was no sign of foul play and no indication anyone had entered his apartment on the night he’d died.

It was a conclusion that had appeared to suit everyone, including his partner, Zac, who seemed determined to blame himself. And although Kate did not believe the verdict for a single second, she had the uncomfortable sense it might have suited her, too, as she wrestled with the collapse of her marriage.

She opened the account of Rav’s movements, such as they could be determined, in Geneva in the twenty-four hours before his death. Suzy had also attached the CCTV log from a newsagent opposite the entrance to the offices of the lawyer Rav had said he was going to see. It confirmed that, whomever he had met, he had not been there.

She read Suzy’s report of the events in Berlin. It ended with a simple conclusion: On the balance of probabilities, it seems likely the Russian state security apparatus had been tipped off to expect us.

Kate thought about the last chapter in this file, which she had no intention of writing: that somehow they’d known she was crossing into Russia to meet Sergei.

‘You could say they’ve been expecting us at every turn,’ Suzy said.

Kate spun violently around. ‘Jesus, you gave me a shock.’

Suzy stood by the door, arms crossed, eyes fixed upon the file open on the computer. Her petite, slender face was much less pretty when she was angry. ‘Julie said you were in Finland meeting a contact.’ Kate didn’t confirm or deny it. ‘I don’t appreciate being kept in the dark, Kate.’

‘Incredibly, not everything is about you.’ Kate turned back to her computer. The questions the files seemed consistently to ask were preferable to those from her subordinate.

‘It would have been courteous at least to let me know you’d be gone for a few days. I’ve looked a total idiot.’