It was Herm himself whom Charles pondered now: how old would he be, had he married and had a family, would he ever settle, were medicine and spying the twin poles of his existence, did he do it for love or duty, how long might he last when at any moment an IS extremist might suspect him or a Russian bomb might haphazardly fall close? The Office was presumably paying him or putting money aside and would resettle him if he survived, but was that enough for what he was doing, the risks he was taking? For everyone else on that email chain, from Downing Street downwards, it was a job; they went home every night. But for Herm, as for every spy, there was no such thing as down time, no such thing as time off. Spying was his life and might easily become his death. Every minute he lived through, waking or sleeping, was spent under threat of exposure.

Charles was still gazing towards the river when Gareth arrived, fashionably tie-less, his suit jacket slung over his shoulder. ‘Bloody JIC,’ he said. ‘Have you seen what the next paper’s to be? A report on international adherence to climate change objectives, the idea being that we find out who’s cheating by supplying made-up figures so that we can put diplomatic pressure on them to reform. Soft power gets softer by the day.’

Charles stood and indicated the armchairs by the coffee table. ‘Drink of something?’

‘Whisky, I need a whisky. Splash of water, no ice.’

Charles poured himself the same from his drinks drawer and took the other chair. They talked about the JIC – Joint Intelligence Committee – for a while, speculating about its survival now that the National Security Committee had usurped an important part of its function. The latter was chaired by the prime minister or other senior ministers and so Charles and the other heads of agencies naturally attended that, delegating the JIC, which they had formerly attended, to their deputies.

‘The problem with the JIC is its passion for consensus,’ said Gareth. ‘Always has been. Makes their reports so bland they’re like – well, like water without whisky. Not that I’m accusing you of being stingy.’

They both smiled. ‘Timber Wolf,’ said Charles. ‘This seems a good time to map out where we’re going. Where we hope to go.’

‘I heard this afternoon that his latest has gone down very well, especially in Number Ten. The Brexiteers are gagging for more.’

‘And in order to work out where we’re going we need to be sure about where we are.’ It was a shot across the bows. Gareth nodded, with a slight tightening of the flesh around his mouth. Charles tried to sound as if he were thinking aloud. ‘First thing we need to get straight – I need to get straight, in my own mind – are his sub-sources. Who are they, exactly?’

‘Well, basically the negotiating team.’