The Kogans have finished their dinner. The dishes from their meal are stacked up ready to be taken to the kitchen for washing; Lidiya is reading and Mikhail is doing puzzles. With the children close by, Vera keeps her voice low.

‘They’re lying to us, Yuri. We’re told that happiness is living in the Soviet Union under the protection of our great leader Stalin. But look at the reality.’ She takes a deep breath, and the words pour out of her. ‘We live in a room with four people and share a bathroom with fourteen. It’s been months since we last saw a piece of fruit. Our shoes are reinforced with cardboard and our socks are a tangle of darning. The electricity is unreliable; for hours at a time we’re reduced to using candles, and the supply of candles invariably falls short of the demand. In the battle between a heated building and the freezing months of winter, it’s the winter that always wins. The faucet in the bathroom has been broken for six months, and there’s no indication it’ll be fixed any time soon. I’ve spent a fair percentage of the past year queuing for goods that have often disappeared by the time I reach the top of the line. No matter that we feel demoralised and miserable, this, according to our great Soviet leaders, is happiness.’

Yuri is about to speak, to placate his wife. But Vera is not finished.

‘I’ve no complaint against the Department for Agitation and Propaganda. After all, there’s nothing wrong with persuasion, not when the message is right. But what if persuasion takes a form that obfuscates the truth? Even deliberately deceives?’

Snow is still on the ground, the river is still under ice, and heaped across the river’s frozen surface and creating a weird, other-worldly vista are icy hillocks now grey in the grimy air. The cityscape remains locked in winter, but already the days are longer, and at seven o’clock it is light outside. Yuri twists around and pulls the curtain across the window.

Vera is speaking quietly, but her distress is quite clear. ‘How would we know?’ she continues. ‘After all, if propaganda is effective you don’t recognise you’re in its grip.’

He shakes his head slowly, he has no more answers than does Vera. What they both do know is to keep their doubts to themselves. There are spies at work, spies in the kitchen, spies on the stairs, spies on the trolley bus, spies in the shop queues. People denounce others before they themselves are denounced. People denounce in order to prove their loyalty.

Yuri, like so many mathematicians, is recruited to work on the All-Union Population Census. In what appears to be grand work for the society he has long believed in, he buries his small doubts, and he’s determined to convince Vera to do the same with her larger ones. He tells her that the census, ordered by Stalin himself, will prove the success of the revolution.