She couldn’t look at him. At the belief in his eyes. Instead she concentrated on the slender stem of her glass, as fragile and breakable as Papa’s back in that labour camp. A nerve pulsed in her jaw and she placed a hand over it.

‘Comrade Malofeyev-’

‘Call me Dmitri.’

‘Dmitri.’ She smiled and flicked a stray lock of hair from her cheek. For a second she was distracted by a smartly dressed man and woman at a table across the room. Both staring at her. She looked away. Was it her clothes? Was she so obviously all wrong in a place like this?

‘Dmitri, if I were searching for someone else, as well as for the Chinese Communist I mentioned earlier, someone in Moscow, would you be willing to help me find this person?’

He studied her carefully, his gaze alighting on each part of her face, even on her throat as she swallowed, and she knew she’d just leapt on to the stepping stone right in the deepest part of the river.

Fog rose from the River Moskva. It slunk in long tendrils across the road, sneaking up to front doors and unexpectedly swallowing people whole when they emerged from their homes into the street. Sledges slid into it and vanished.

Alexei stood still. He had no desire to move. He felt like a ghost, barely there, a lone figure caught between reality and non-reality. Each time he heard footsteps on the broad steps, leading up to where he was propped against the stone pillar of the Cathedral’s entrance, his breath quickened with expectation. This time it was real, not a figment of his exhausted mind.

A woman drifted out of the white layers of moist air rising towards him. He held out a hand to her but she veered away abruptly and he realised she thought he was a beggar. The streets were full of them. She had heavy black eyebrows and thick ankles, he registered that much. Not Lydia after all then. Nor Antonina, whose ankles were slender, the bones beautifully carved. He yearned for her touch now to rid him of this deadness. His eyes closed as the cold crept with sharp fingers through his thin jacket and into his blood, making it sluggish and stubborn, painful as it pushed through his veins.

It was gone noon. Long gone. He forced his eyelids open in case he missed her. In this fog she might pass three feet from him and not know he was there. He tilted his head back but the golden domes of the Cathedral of Christ the Redeemer had ceased to exist, stolen from sight by the dank air and something fluttered on the edge of his thoughts. Something about this church. He’d read something. That was it. It was going to be blown up. Involuntarily he stepped away from the pillar as if it were about to explode, but immediately felt the absence of its stone solidity at his back. Is that what worshippers would feel, the loss of solidity, of belief?

He walked slowly round the outside of the great towering building till he came to the River Moskva at its back, where the water flowed in ripples of steel. It looked so hard, so substantial. He started to cross the bridge that spanned it but had to stop halfway because the muscles in his legs were shaking with exhaustion. He leaned on the parapet and was aware that he had disappeared. This close to the river he was wrapped in a cocoon of fog, invisible and unknown.

It didn’t matter, Lydia wasn’t coming. Had she lied to him? No. He shook his head. She didn’t lie to him in the letter, he was certain. Either she had left Moscow – with or without their father – or she was unable to make it to the church. Whatever the truth, he couldn’t help either of them now, not Jens Friis, not Lydia. But he missed her, missed her laugh and her stubborn chin, and the way she knew exactly how to get under his skin. And her moments of unexpected gentleness, he missed them more than ever now.

The journey to Moscow had cost him dear and stripped him of everything, both physical and mental. It had taken all his strength to get here, walking for weeks without end, no food, losing track of time. He leaned his head over the bridge and stared down at the cushion of thick white air that hung just below him. It looked tempting. On that soft pillow he could rest at last and dream again of galloping through the autumn woods beside his father.

The group of prisoners stood alone in the central courtyard behind heavy studded doors. Nine men, three women. In the back of a truck, sheltering out of the bitter wind, two soldiers watched over them, unseen in its dark metallic interior with rifles across their knees, cigarette smoke warm in their lungs. Outside snow fluttered down in spinning spirals, settling on hats and shoulders, yet despite the cold and the tall gloomy buildings that loomed over them, blocking out what little winter light filtered down, each of the prisoners was smiling.

It was always the same. A day free from the rattle of locks. No jangle of keys, no interminable grey corridors that led only to more locks and more keys. Anticipation prickled their skin. It reminded Jens of when he was a young man in St Petersburg, standing in the stable courtyard waiting for the carriage to arrive to whisk them away to the summer palace for the day. Well, today wasn’t an outing to any palace. Far from it. Just to a gigantic hangar in a well-guarded field surrounded by dense forest. Not that he’d ever seen the forest here, but he’d heard the wind in the branches, the sigh of wooden limbs as they flexed and shivered. It was a sound he’d listened to a million times in the forests of Siberia, a sound as familiar as his own breath.

‘Jens.’

‘Olga,’ he smiled. ‘No need to be nervous.’

‘I’m not nervous.’ She said it breezily. ‘It’s the noise of the wheels I hate, that’s all, as they drive over rough ground. Like bones being crushed.’

Olga was a skilled chemist, no more than forty but she looked older, the lines round her mouth etched deep after eight years’ hard labour in a lead mine. Her body was fleshless, stick thin, and she complained of stomach pains whenever she ate her meals. Here in this prison they were decently fed, a world away from the labour camps. They routinely devoured more protein in one week than they’d previously had sight of in a whole year. Stalin was feeding them up the way a farmer fattens a pig before slitting its throat. To get the best out of them. Stalin wanted the best out of their brains.

The prison doctor declared that Olga’s pains were all in her mind and he might be right. Guilt, Jens believed, guilt was eating her up each time she pushed a forkful of food past her lips, because her daughter was still out there in the lead mine where bones were regularly crushed under rockfalls.

‘I hate going in the truck,’ Olga muttered.

‘Just imagine that you are in a horse carriage,’ Jens urged, ‘trotting down the Arbat to take tea at the Arbatskiy Podval café. That would put a smile on your face. Cakes and pastries and sweet strawberry tarts and-’

‘Mmm,’ murmured a younger woman nearby, ‘plum tart with cream and chocolate sauce.’

‘Annoushka, you never think of anything but food,’ Olga scolded.

‘Food is comforting,’ Annoushka confessed. ‘And God knows we all need comfort in this place.’

‘If you keep eating the way you do, you’ll soon be too fat to fit in the truck,’ Olga teased.

It was true. Annoushka did eat a lot, but so did most of them. They’d been starved for too many years to let even a crumb remain uneaten on a plate. Like squirrels, they hoarded nuts for the winter that was sure to come again one day soon, once Stalin and Kaganovich and Colonel Tursenov had finished picking their minds clean. Behind them the truck’s engine started up, the noise of it rebounding off the high courtyard walls, and a plume of black exhaust billowed into the chill air. The two soldiers in the back jumped out and held open the rear doors.