He glanced outside the office, then shut the door, locked it, turned to me. The mood had changed. I let him work his way out of the silence.

‘We know she pursued Craig Bryant. All Carter knows for now is that there was a leak of some kind, somewhere along the line. They want to sue Auracle.’

‘That’s going to get messy.’

‘We’re going to make sure it doesn’t. We’re going to bury the whole Joanna thing. Understand?’

‘No, I don’t understand.’

‘Are there any other copies of the footage showing Joanna in Vishinsky’s car?’

I felt myself thrown off-balance. My muscles tensed, and I glanced across the room for objects I could use as a weapon if it came to blows, wondered how much of his training Walker remembered. Where did he get that information? Shomko? From taps on me? There was no shortage of ways.

‘Your pisshead police officer needs to forget he ever saw it.’

‘And the computer-generated clip I showed you? What has that got to do with spying for Vishinsky?’

‘What’s it got to do with anything? What are you really doing here, Elliot?’ He was too cool, too experienced for all-out anger. And he held cards. ‘Both you and Joanna have been on a caution list since 2010, with some heavy question marks by your names. Security Branch are very, very keen to speak to you right now, as you can imagine. So be thankful you’re in here and not Belmarsh. I may be the only one still willing to trust you.’

It was possible, but the feeling wasn’t mutual. If he didn’t trust Joanna he didn’t trust me. Manage the immediate situation, I thought: Russian incursion, a possible bomb in Astana. Then get out.

‘Do you know where she is?’ I asked.

‘Moscow, I expect.’

‘I was hunting her for you.’

‘I don’t remember asking you to come over here. Joanna Lake’s seen in a car connected to Vladislav Vishinsky on Saturday the twenty-fifth. Over the next forty-eight hours there’s huge Russian activity: flights booked, meetings arranged, money transferred. The first troops move down to the Kazakh border. We’ve checked imagery from the last week down to minutes and hours. Vishinsky arranges an emergency meeting at which he presents data to Gazprom. And there’s a payment of half a million dollars into a Cayman Islands account Joanna set up the previous month.’

He produced the last fact with a flourish, and enjoyed watching me hesitate.

‘How do you know?’ I asked.

‘We know.’

‘That’s my point. She’s a trained officer. You think she sets up a visible account in the Cayman Islands?’

‘Elliot, do you really think it’s impossible she’d do this?’

‘She’d do it better. This is being handed to us.’

‘So why didn’t you tell us about the footage from Lieutenant Shomko?’

‘Why would I trust you?’