‘But –’

‘My treat. I spend my life serving food to other people. If I’m going to have one blow-out, I’m going to have it here, in a Michelin-starred restaurant, surrounded by good-looking Jean-Pierres. I’ve earned it. And, come on, I owe you one.’

They eat in the restaurant. Mo is garrulous, flirts with the waiting staff, exclaims uncharacteristically over each course, ceremonially burns Paul’s business card in the tall white candle.

Liv struggles to stay engaged. The food is delicious, yes. The waiters are attentive, knowledgeable. It is food Nirvana, as Mo keeps saying. But as she sits in the crowded restaurant something strange happens: she cannot see it as just a dining room. She sees Sophie Lefèvre at the bar, hears the echoing thump of German boots on the old elm floorboards. She sees the log fire in the grate, hears the marching troops, the distant boom of guns. She sees the pavement outside, a woman dragged into an army truck, a weeping sister, her head bent over this very bar, prostrate with grief.

‘It’s just a painting,’ Mo says a little impatiently, when Liv turns down the chocolate fondant and confesses.

‘I know,’ Liv says.

When they finally get back to their hotel, she takes the file of documents into the plastic bathroom and, as Mo sleeps, she reads and reads by the harsh strip-light, trying to work out what she has missed.

On Sunday morning, when Liv has chewed away all but one of her nails, the matron calls. She gives them an address in the north-east of the city, and they drive there in the little hire car, wrestling with the unfamiliar streets, the clogged Périphérique. Mo, who had drunk almost two bottles of wine the evening before, is subdued and tetchy. Liv is silent too, exhausted from lack of sleep, her brain racing with questions.

She had been half expecting something depressing; some 1970s box in liverish brick with uPVC windows and an orderly car park. But the building they pull up outside is a four-storey house, its elegant windows framed with shutters, its frontage covered with ivy. It is surrounded by neatly tended gardens, with a pair of tall wrought-iron gates and paved paths that lead into separate closeted areas.

Liv buzzes the door and waits while Mo reapplies her lipstick – ‘Who are you?’ Liv says, watching her. ‘Anna Nicole Smith?’ Mo cackles, and the tension clears.

They stand in Reception for several minutes before anybody pays them any attention. Through glass doors to the left, quavering voices are raised in song, as a short-haired young woman plays an electric organ. In a small office, two middle-aged women are working through a chart.

Finally one turns around. ‘Bonjour.’

‘Bonjour,’ says Mo. ‘Who are we here for again?’

‘Monsieur Bessette.’

Mo speaks to the woman in perfect French.

She nods. ‘English?’

‘Yes.’

‘Please. Sign in. Clean your hands. Then come this way.’

They write their names in a book, then she points them towards an antibacterial-liquid dispenser and they make a show of rubbing it thoroughly over their fingers. ‘Nice place,’ Mo murmurs, with the air of a connoisseur. Then they follow the woman’s brisk walk through a labyrinth of corridors until she reaches a half-open door.

‘Monsieur? Vous avez des visiteurs.’

They wait awkwardly by the door as the woman walks in and holds a rapid-fire discussion with what looks like the back of a chair. And then she emerges. ‘You can go in,’ she says. And then: ‘I hope you have something for him.’

‘The matron said I should bring him some macarons.’

She glances at the expensively wrapped box Liv pulls from her bag.

‘Ah, oui,’ she says, and gives a small smile. ‘These he likes.’

‘They’ll be in the staffroom before five o’clock,’ Mo murmurs, as she leaves.

Philippe Bessette sits in a wing-backed chair, gazing out at a small courtyard with a fountain; an oxygen tank on a trolley is linked to a small tube taped to his nostril. His face is grey, crumpled, as if it has collapsed in on itself; his skin, translucent in places, reveals the delicate tracings of veins underneath. He has a thick shock of white hair, and the movement of his eyes suggests something sharper than their surroundings.

They walk around the chair until they are facing him, and Mo stoops, minimizing the height differential. She looks immediately at home, Liv thinks. As if these are her people.

‘Bonjour,’ she says, and introduces them. They shake hands and Liv offers the macaroons. He studies them for a minute, then taps the lid of the box. Liv opens them and offers him the tray. He gestures to her first, and when she declines, he slowly chooses one and waits.

‘He might need you to put it in his mouth,’ Mo murmurs.

Liv hesitates, then proffers it. Bessette opens his mouth like a baby bird, then closes it, shutting his eyes as he allows himself to relish the flavour.

‘Tell him we would like to ask him some questions about the family of Édouard Lefèvre.’

Bessette listens, and sighs audibly.

‘Did you know Édouard Lefèvre?’ She gets Mo to translate, waiting.

‘I never met him.’ His voice is slow, as if the words themselves are an effort.

‘But your father, Aurélien, knew him?’

‘My father met him on several occasions.’

‘Your father lived in St Péronne?’

‘My whole family lived in St Péronne, until I was eleven. My aunt Hélène lived in the hotel, my father above the tabac.’

‘We were at the hotel last night,’ Liv says. But he doesn’t seem to register. She unrolls a photocopy. ‘Did your father ever mention this painting?’

He gazes at the girl.

‘Apparently it was in Le Coq Rouge but it disappeared. We are trying to find out more about its history.’

‘Sophie,’ he says finally.

‘Yes,’ says Liv, nodding vigorously. ‘Sophie.’ She feels a faint flicker of excitement.

His gaze settles on the image, his eyes sunken and rheumy, impenetrable, as if they carry the joys and sorrows of the ages. He blinks, his wrinkled eyelids closing at half-speed, and it is like watching some strange prehistoric creature. Finally he lifts his head. ‘I cannot tell you. We were not encouraged to speak of her.’

Liv glances at Mo.

‘What?’

‘Sophie’s name … was not spoken in our house.’

Liv blinks. ‘But – but she was your aunt, yes? She was married to a great artist.’