Charles nodded. ‘The only reason I can think of is the most unpalatable one – there aren’t any.’ He finished his tea. ‘Thing is, what am I going to say to Robin Woodstock in the Foreign Office in fifty minutes? I don’t want them to go off the deep end and mistrust all Timber Wolf reporting – which, with a handful of other cases elsewhere, is what our reputation in Whitehall rests on at the moment – but nor do I want to have to creep along subsequently when it all blows up in our faces and confess that we’ve been worried about this for a while but didn’t like to say so. As spies, we are midwives to truth. We have to be, that’s our mission. We deceive to reveal. Our obligation is to deliver, however unpalatable.’

‘I really can’t manage any more of this.’ She pushed her tea aside. ‘Do you have to say anything yet? Why not wait until you have a full story to tell that you know to be true rather than half a story and a raft of unverified suspicions? After all, what can Robin do with half a story – react, not react, wait and see? By sharing it you’re simply foisting our uncertainty on him, as if you’re absolving us of sole responsibility. Of course, I know I’m playing devil’s advocate here, having raised the doubts myself.’ She smiled. ‘I think you should say as little as you can and meanwhile we investigate.’

‘How?’

‘You’ve forbidden Gareth any more Timber Wolf meetings?’

‘For the time being.’

‘Someone else should see Timber Wolf.’

‘You?’ He could imagine the effect on Gareth. But Sonia would get to the bottom of it. She would be a mild-mannered and merciless interviewer, grinding very small.

‘Not me, much as I’d love to. Gareth can’t stand me, he’d probably resign. No, it needs someone who would carry authority with Gareth, whatever emerges from Timber Wolf, good or bad. It should be you. He might just accept your doing it. Might.’

The idea had already occurred to Charles, without his thinking seriously about it. As was often the case with half-formed ideas, it gained substance through having been suggested by someone else. It might also bring him a step closer to resolving a deeper, still unspoken worry he had about the case. Unspoken even now to Sonia. ‘He wouldn’t like it.’

‘Would he have to know, until afterwards? You could contact Timber Wolf directly, pretending to be Gareth. Then you turn up instead.’