I wondered what Joanna was doing risking her life for an oil company. Maybe, after all the smoke and mirrors of Shefford, there was something honest about oil. It was real. Maybe she wanted to cash in on her experience. We’d need money, she had said. I couldn’t bring myself to believe she was doing this for us. I imagined that moment of decision: the thought of Kazakhstan, ice and emptiness. The simplicity of it, compared with the hot and complicated places where we had operated on dubious pretexts. When Walker and I met at the Special Forces Club his job offer had reminded me of the conversation that led me over the threshold into Six: offhand, almost childish. ‘Fancy a bit of adventure? A challenge? Not many rewards, but you’ll have a chance to work off your own bat, explore the world a bit.’ I had the sense that he wanted me there in the way we want good friends to share our vices, for both physical and moral companionship. What enticed Joanna to Vectis, of all companies? She wasn’t someone who stumbled into things.

‘Do Saracen know about any of this?’ I asked.

‘Our clients aren’t interested in operational details. They’re looking for oil, not missing investigators.’

‘And they won’t notice the sudden absence of briefings?’

‘That’s our problem. Obviously this is an embarrassment.’

‘I hope, wherever Joanna is, she’s not too embarrassed.’

Walker didn’t bother defending the crassness.

‘What do you know about her last movements?’ I asked.

‘She filed a report at nine p.m. on the evening of Saturday 27 November. Dined alone at her hotel. Staff saw her go up to her room, leave again around ten-thirty. That’s the last we’ve got.’

‘No pickup on cameras? Card use? Phone signal?’

‘None we’ve got so far.’

The amount of resources not being tapped was agonising.

‘Reported this to the police? They might know the terrain better.’

‘Vanessa McDonald was supposedly investigating police corruption. Joanna Lake was a private-sector spy. Which of them do you want the police looking into?’

I thought through the legal situation. ‘Clear as an oil spill’ would be the generous way to put it: a former MI6 agent entering on fake papers, spying on Kazakh citizens, installing surveillance, hacking God knows what, and then Vectis waving guns around when it went wrong. As if sensing this – and keen for an out – Walker said, ‘You worked together. Could this be something from the past catching up?’