We dipped towards Astana and the intercom came to life, the pilot clearing his throat and informing us that it was minus 8 on the ground and there were roadblocks around the city. The time was 3.15 p.m. Beneath us, two C-130 military transport planes sat fatly on the airport runway, a line of 50-ton army trucks parked along the perimeter fence.

Touchdown was smooth. We exited via a lounge with car magazines and a white leatherette sofa. No passport control, no DV camera in the face. I was met by a GL5 Mercedes, with Walker in the back. I got in. We started heading around the outskirts of the city.

‘What took you east?’ Walker asked.

‘I was following a lead.’

‘And you found Akan Satayev.’

‘He found me. So did Russian special forces on Kazakh soil.’

‘Definitely Russian?’

‘Russian, Serb. Probably Sigma Group.’

‘We’re going to the Saracen HQ. They need to hear what you saw.’

I played along. I was being invited into the heart of a company whose actions threatened to provoke a Russian invasion. I needed to know what they were planning.

‘The President is terrified of upsetting Moscow,’ Walker said, after another moment. ‘That’s our problem right now.’

‘Does the Oil Ministry know how big it is? Over five billion barrels?’

‘As of yesterday, it seems. They’re asking 8.9 billion dollars. Saracen have secured credit up to eight. They’re trying to get it within that. Money’s not the biggest problem. If they get the Conqueror field for eight they’ve got a bargain.’

‘Conqueror?’

‘That’s what they’ve named it.’

‘Jesus Christ.’

We passed striped office complexes, emerald towers, clouds held in glass, moving around corners.

‘Can I ask,’ he said, cautiously, ‘did you have any suspicions about her? Ever?’

‘No.’

We pulled up in front of the Saracen HQ. There was already a wall of four armoured black Lexus limousines with motorbike outriders waiting.

‘I want you to meet Robert Carter,’ Walker said. ‘I told him you know what’s going on.’

Armed guards searched my pockets, ran a scanner around my body then waved us through. Everything was calm until we got to the sixth floor, where over sixty Saracen personnel were working phones and computers. I was brought up to speed as we marched through, past geological surveys and dense spreadsheets. Experts across Saracen’s divisions had been ordered to abandon everything else and number-crunch the bid. The European Investment Bank had their own people coming over to conduct a feasibility study. On the plans I saw, wells stretched out in all directions once they got underground, thousands of feet long, running to multiple reservoirs. Tight oil: light crude held in shale, which meant digging deep and fracking.

A meeting with the President and the head of KMG was lined up for 8 a.m. tomorrow. Two hundred more GL5 contractors were set to roll into Kazakhstan by nightfall.