Nicolas squints. The roof has a greenish tinge. ‘I might say aquamarine.’

‘Excellent. Aquamarine.’ Rachkovsky savours the word like a peppermint comfit. ‘Speaking of literary pursuits, I’d love to have your opinion of Mulhouse’s creation. It’s a work in progress and we’re still refining it.’

‘I’m not sure I was in a mood to appreciate it.’

‘Very true. Context is everything. Let me offer you some.’ Rachkovsky leans on a headstone and knocks some dried mud off his shoes with his walking stick. ‘Bear this in mind: the ordinary Russian, like the ordinary man anywhere, occasionally feels discontented, occasionally feels disparaged by the way of things. At times like that, he might feel that revolutionary politics says something of interest to him. It would only be natural. What we want to do is to remind him of the profoundly un-Russian character of these people. We want to remind him that the working man has worse enemies than the status quo.’

‘But you and I are Jews.’

‘What of it? Our ancestors, the Khazars, worshipped the sky god Tengri, and left ribbons on trees to placate elves. We’re beyond such fairy tales. You and I are free men. We both realise that God is dead, man is alone, and everything is possible. But that is strong meat which not many people are capable of digesting. Besides, I don’t think of our project as anti-Semitism as such; I see it more as a literary device: the Jew as an allegory of modernity.’

‘Really? That seems a bit sophisticated for its intended readership.’

Rachkovsky laughs. ‘You’re being very pi, dear boy. It’s unlike you. After all, the thing’s a bauble.’

Above their heads, one of the slow-moving clouds drifting to the south takes on the shape of a fish; another thins and momentarily resembles a child with a distended head. ‘My future is not in the Third Section,’ says Nicolas.

‘I’m sorry to hear it,’ Rachkovsky says. ‘I’d rather hoped you’d reconsider. You’re an excellent agent and could look forward to a stellar and lucrative career.’

‘My mind’s made up.’

‘Very well. That’s your choice. I don’t threaten. It’s not my style. But working for the Third Section imposes life-long obligations.’

‘I understand,’ says Nicolas.

‘Of course you do.’

Rachkovsky has a carriage waiting. He doesn’t offer Nicolas a lift. As he climbs in, his big, linen-covered backside sticks out awkwardly and Nicolas has an urge to kick it.

‘How’s your friend Skobelev doing, by the way?’ he asks. Before Nicolas can reply, Rachkovsky throws his head back and brays like an ass. The sound is loud, jarring and uncannily accurate. The coachman flicks the reins and the wheels move off, clattering over the cobbles. ‘Farewell, Nicolas. And be careful.’ Rachkovsky points up in the air with his stick: ‘It looks like heavy rain.’