Throughout the painful months which followed, throughout operations, swellings and pain, Abigail kept mistrusting him. When the first procedure succeeded in recreating her left cheekbone, she did – for an instant – catch a vague glimpse of the self she had once been. But it faded fast. The operations went on. More injections. More stitches. More bandages were used, became bloodied, were changed. Drains were inserted into her face, then removed. Every time the procedures varied. Every time Ben told her she was making progress. She was sick with the anaesthetics; she cried in the side ward at night, on her own, because she had no family, only a father in France, too weak to travel. In the grim Whitechapel Hospital Abigail Harrop lost herself and turned to the nurses for support. Only gradually, slowly, did she begin to believe. Some little triumph of healing had restored her eye socket almost to its original. And for the first time in over a year, Abigail saw herself and began to climb back.

She had had only one moment of doubt after that. Overhearing two nurses talking, Abigail had heard one refer to her as Ben Golding’s personal masterpiece. His creation. Jealousy had sparked the remark, but instead of being unnerved Abigail had felt unexpectedly pleased. Whatever his motives, what Ben Golding had promised her, he would deliver. This man – and only this man – would give her back what she had lost.

But she never counted on loving him. Grateful, in his debt, yes. But to love him? That had never entered her mind, even though it would have been an obvious response. What people didn’t realise was that Abigail didn’t expect anyone – least of all Ben Golding – to find her attractive. So when, long after she had ceased to be under his care, Ben told her how he felt, Abigail’s shock was genuine. She withdrew, confusing him. She rejected him, making him all the more certain of his feelings. And in the end she accused him of wanting her only because she was his guinea pig.

And he’d burst out laughing.

Her thoughts came back to the present. ‘Get back home, will you? As soon as you can, hey?’

He felt the pull over the line, the jerk of sensuality. ‘Tomorrow—’

‘Can’t come soon enough.’

An hour later, as Ben left the hotel, the sky suddenly darkened to indigo, lightning following within minutes as a hot wind blew across Madrid. Looking out of the window of his hired car, he fought the temptation to return to London immediately. Having once been passionate about Spain, he now found the country oppressive. But he had promised he would visit Leon, and so, reluctantly, he turned in the direction of his childhood home.

A moment later he was crossing the familiar river, freckled with birds and drowning reeds, a heat haze making the road shimmer before him. It had been urbanised when they were children, but now the area was even more built up, unremarkable, almost down at heel. His childhood tap-dancing before his eyes, Ben neared his old home, the site of the Quinta del Sordo close by. Parking in the driveway, he stared at the weather-beaten whitewashed rectangular house.

Maintained intermittently for over two hundred years, the place was mottled with patches of repair, like a face freckled with sun damage. The gable where summer birds had once roosted was now closed off with netting, the bay window on the first floor barred with ornate ironwork. Ben’s gaze moved upwards to his childhood bedroom, separated from his brother’s by a shared bathroom. Without even trying, he could remember the sound of faulty pipework banging at night, and the paper kites Leon and he had exchanged through the open bedroom doors, many landing in the chipped bathtub between. But more than anything Ben remembered the underlying disquiet of the house. The muted but ever-present melancholia.

‘You came,’ Leon said warmly, walking over to him.

Smiling, Ben got out of the car to find his brother accompanied by an athletic, deeply tanned woman in a white linen dress. Shielding her eyes from the sun, she smiled as Ben approached.

‘I’m Gina. And I’m so glad to meet you.’ Smoothly, she then moved between the two brothers as the three of them walked into the cool interior of the house. It smelt to Ben of memory, poignant and unexpectedly hostile. ‘You’ll stay for lunch with us?’

‘I’d like that.’

‘Nothing fancy, but your brother likes my cooking. Still, what would Leon know about food? He’s an academic,’ Gina replied, changing the subject deftly, her American accent barely perceptible. ‘Apparently you don’t think much of our other house guest. Leon said you thought it was unlikely to be Goya’s skull.’

‘Well, it’s a long shot,’ Ben admitted. ‘Turning up like that, out of blue, when people have been looking for it for decades.’

She tilted her head to one side. ‘But it could be proved for certain one way or another?’

‘There are tests which would authenticate it,’ Ben agreed, ‘or not.’

‘Leon knows everyone in the art world, and he’s so well thought of in Madrid that the authorities have let him have free rein. Anyway,’ Gina went on lightly, ‘I’m going to get lunch ready and leave you two to have a talk. But no longer than half an hour, OK?’

Watching her walk away, Ben felt a sudden sharp tug on his arm, Leon hustling him towards the staircase. He was nervous, edgy, his unease obvious in the erratic movements of his hands.

‘Before I show you the skull, there are some other things I thought you might want to see,’ he explained, hurrying his brother up the stairs to the shady narrow landing which led to the servants’ quarters.

Fiddling with his shirt collar, Leon walked on quickly, finally opening the door which led to Detita’s apartment. As though still children, both men hesitated for an instant before walking in, Leon immediately moving over to the window, his back turned to the room.

‘I was going to sort out her things, but I couldn’t get round to it. Gina said she would, but I thought you might like to have a look first. You know – see if there’s anything of Detita’s you want to take. To remember her by.’

Slowly, Ben looked around the room. A heavy wrought iron chandelier suspended from the high ceiling, wooden shutters open to let in some air, a carved bed draped with white muslin and a quilt the colour of water reeds. Pulling open the wardrobe door, he found himself face to face with the print dresses and jackets he remembered so well, a row of shoes lined up like piano keys. And the scent of something, somebody, well known.

‘She had papers too,’ Leon said, and Ben turned and walked over to a side table where his brother had laid out several notebooks.

Apparently Detita had left behind parts of missives, parts of photographs, parts of cards. Nothing whole – just portions, incomplete and unreadable. And in among the meticulous chaos were images of Goya, his self-portraits and a fragment of the painting of the lunatic asylum. Beside those was a drawing of the Quinta del Sordo and one other: a disturbing image of a skeleton, half alive, half dead, writing the one word on black earth: Nada. Nothing.

‘Look at this,’ Leon said, picking up a hairbrush from Detita’s dressing table. Her scent bottles were still sitting in the shade, lying beside a copy of The Manuscript Found in Saragossa and a History of the Occult.

‘She had strange tastes.’

‘Never tried to convert us, did she?’

Ben looked up. ‘To what?’

‘Catholicism.’

‘She tried damn near everything else,’ Ben replied. ‘All those bloody stories she used to tell us! When I was little I was always waiting for those horses coming over the bridge to get me.’

To his relief, Leon laughed. ‘Remember when you came back from school when you were fifteen and you went out at midnight and clicked your fingers over and over again just to prove that nothing would happen? Detita went crazy, said you would bring the Devil.’ He shrugged. ‘I admired you for that. I’d never have dared.’