Charles knew only too well what his legal advisor was like, a paunchy, self-important man seconded from the Home Office who saw his job as primarily to stop people doing things. It had been hard enough getting him to put his stamp on the Tresco submission before it went into the Whitehall mill. Once he had his teeth into an issue like this he would be remorseless. There would be no end of complications, possibly even an inquiry into agent payments in general, which would rule that in future they had to be signed for by the agent in the presence of a visiting finance officer. Not to mention declaration to HMRC. He would probably also insist that security withdraw Gareth’s vetting certificate, which was effectively to sack him since no one was allowed to work in SIS without one. ‘Naturally, I don’t want to tell anyone until we’ve decided whether or not we can exploit this in any way. But I need to get security on side.’

‘Are you sure Gareth doesn’t know you know about his keeping half the money?’

‘He didn’t show any sign of unease when I mentioned it. We’ll have to assume that it will come out in some way if he talks enough to Timber Wolf. But that’s all right. We might want him to carry on as he is.’

‘Carry on?’ It took a lot to surprise Sonia. ‘Carry on with the case?’

‘Yes, depending on what your Cheltenham friend can tell us. Have you got authority for what you want to do with them, by the way?’

‘Almost.’ She tried to hide her smile with her glass.

Charles looked at her, then let it go. ‘We need to know of any contact between Gareth and Timber Wolf after my lunch in Brussels. They obviously were in contact but it would be useful to know who initiated it and whether there has been further contact since.’

‘Bear in mind they might not be able to say what was said. Yet.’

‘Also, anything they can produce on Timber Wolf’s contact history before the lunch as well as after it. With people other than Gareth, I mean. Who did he talk to and when.’

‘What exactly have you got in mind?’

‘What I suspect you may already be thinking.’ They looked at each other for several sedate ticks of the Cumming clock.

‘You mean Timber Wolf might be a double agent, a DA?’