‘That’s because you operate at too high a level. Down at desk level people know things and can do things.’ She opened her clipboard. ‘Mr Rodney Rushlake to the Eurostar to Brussels on Wednesday evening. Single, just hand baggage. That’s one of Gareth’s old aliases for which he still has documentation.’

‘I thought once they were closed we no longer had any docs or any record of them.’

‘We don’t but MI5 do. When they were created we used to log them with MI5 and they logged theirs with us in case two people were issued with the same one. They keep better records than us. We have Mr Rushlake logged as closed but it never was. They have it as still open, complete with bank account, credit cards, driving licence, passport, the full hand. It appears that Mr Horley has kept Mr Rushlake alive for years in case of need, which suggests a long-term criminal cast of mind, if not of actual intent. We can close all the accounts and cancel the passport with a telephone call. And do the same with another of his aliases, which we also had logged as closed and which is still extant. He’s probably got all that documentation with him as a standby. If we closed both down he’d be helpless, unable to travel anywhere or pay for anything.’

Charles again tried to reconcile the Gareth he thought he knew with the Gareth who was now emerging. He must indeed have had a criminal cast of mind, as she called it. Necessary, perhaps, for a good operational officer; you needed guile, a willingness to bend or break rules, an eye for the main chance and a fallback, always a fallback. At least one. But you needed integrity, too, honesty and the self-discipline to use criminal tactics for good ends only. Perhaps a less common combination than Charles had assumed. ‘But if we closed them down he’d know, wouldn’t he? Know we were on to him.’

‘Would that matter? Once he knows he’s isolated and virtually helpless wouldn’t he be more likely to give himself up?’

‘But do we want him to? He might be more useful where he is.’ He told her what had been agreed in Number Ten the previous evening.

‘If you’re to be the message-bearer, what role can there be for him?’ she asked. ‘Whitehall wouldn’t want him involved because they know from us that he can’t be trusted. Quite rightly. That’s why they want you – you just said.’