The cold was deepening, but Paul was getting to know the city. Flush with his earnings, he booked a walking tour. He selected a guide named Angelica from the Real Guides of Russia website. Her page had great reviews, so he put aside the fact that her photo was slightly corny, showing her sniffing a daffodil. But she turned out to be a woeful guide: she drifted rather than led, took him to a closed cathedral, and muddled up the tickets for the Kremlin. He had hoped to be dazzled by tales of Napoleonic battles but she knew as much history as an indifferent high-school student. Still, he didn’t mind too much; he enjoyed her company. Over a drink, she helped him to say her name correctly, with the softer Russian zh: ‘Zh for zhuk, butterfly.’ When he helped her into her champagne-coloured puffer coat, they agreed to meet again.

But it was Darya, not Angelica, who seized his attention, by initiating a brief affair. It took place over four nights in mid-December. For Paul, the whole thing was unexpected, even miraculous. Anton was at his mother’s and Nikolai was away on back-to-back trips (first a work excursion to one of the oil company towns that dotted the tundra of the subarctic north, and then a few days’ skiing with his brother in the Khibiny Mountains).

This was how it happened. Darya, feeling reckless or lonely or both, came to Paul’s door wearing a wrap and towelling slippers. Walking in when he opened, she took his hand and put it on her breast under the wrap. Her hair was damp from the shower but she hadn’t shaved her legs, and in what followed her stubble grazed lightly on his shins. His main contribution to the unfolding of things was to offer her vodka (her reply: ‘I can’t stand vodka’) and to find a condom in the bedside drawer.

That was the first night. He didn’t have time to feel guilty. It just happened and then she left; there was the muffled clunk of the door behind her. But then he wondered how to account for it. Had he unwittingly invited her approach, given her signals? It was true that he’d begun to feel drawn to her, but he thought he’d been careful not to show it. Perhaps he had given away more than he knew with all that effortful not-looking, his studious attempts at professional disinterest?