Gareth’s absence meant there was time for another session with Sonia before Charles confronted him. Not wanting to give the impression even to his private office that there was anything untoward, he arranged another out-of-office briefing, this time over an evening pizza at home in Cowley Street.

‘Since Swinbrook I’ve been through all the Timber Wolf write-ups again,’ said Sonia. ‘I’ve also asked Cheltenham for a printout of his cyber footprint. As with all of us, it’s much bigger and more densely populated than you’d think. Gets around, does our Timber Wolf.

‘Aged forty-seven, born in s’Hertogenbosch, father a lawyer, mother a teacher, educated locally, then at university in Nijmegen where he read law. Then he somehow got a place at ENA, you know, the French academy for administrators through which the entire French elite perpetuates itself. Then the Dutch foreign service and Geneva where he met Gareth, also a number of other of our people and the Foreign Office’s. Next he’s posted to Brussels as part of the Dutch mission to the EU, then he resigns and joins the EU itself. His Brussels contacts are many, as you might imagine, but interestingly they don’t appear to include any of the current EU negotiating team who are so regularly indiscreet with him, according to Gareth.’

‘Maybe because he works alongside them every day so doesn’t need to communicate outside the office.’

‘Maybe. By his own account, he advises the negotiating team on ensuring that proposals emerging from the negotiating process are legally compatible with wider EU policy, particularly ever-closer union. But his office is not on the same floor as theirs. In fact, he’s on the same floor as the president. His official job description – which seems to have emerged only about a year ago – is Advisor to the President on Policy Coherence. Which means everything and nothing, of course.’

‘No indication how much time he spends with the negotiating team, visits their offices, socialises with them or whatever?’

‘None. His wife is Belgian, a former ballerina who teaches dance. Most of their socialising seems to focus around her friends, a fairly arty crowd. He belongs to an EU gym, exercises regularly, takes the boys skating on the Dutch canals in winter. They’re seventeen and fourteen, both at school in Brussels. A pretty comfortable, well-balanced life on the whole, well paid, very low taxes as an EU official, very generous pension. Most other travel is in the course of his work.’

‘Where?’

‘Paris, Berlin, Warsaw, Washington, Beijing, London. Or used to. He hasn’t travelled since the referendum except here, when he met Gareth.’ She picked up a piece of pizza crust from the side of her plate, broke off the end and chewed it slowly. ‘All their meetings since then have been in Brussels, all in suitably expensive restaurants and hotels.’

‘What’s Gareth’s cover for being there?’