‘He never spoke to me. He pretended I did not exist. I think, perhaps, he was afraid of me, of my blindness, of what I could see.’

‘I – I’m so sorry,’ Rosa stammered. ‘I lost my own father b-but . . .’

But he was a wonderful man, she wanted to say. He was everything to me. But she could not say it, it would have sounded like boasting after Cassie’s confession. He broke Mama . . . Sebastian too . . .

‘I wish,’ she said slowly, ‘I wish I’d had an opportunity to see your mother again. Before I left. I never had a chance to say thank you for what she did – I owe her my life. Would Sebastian—’

‘No!’ Cassie spoke urgently, cutting across Rosa’s faltering words. She felt for Rosa’s arm, her fingers closing painfully tight on Rosa’s sleeve. ‘No, for all our sakes, please – the best thing you can do for Mama is forget you ever saw her. And whatever you do please never mention to Sebastian what happened.’

‘But why?’ Rosa said. She matched her voice to Cassie’s – not quite understanding why they were whispering, but Cassie’s anxiety was contagious. ‘I know madness in the family is considered a disgrace by some, but now we’re engaged . . .’

Cassie only shook her head, the ribbons on her hat fluttering in the winter breeze. Her small face was determined, her chin set, and there was something almost like Sebastian’s immutability in her expression.

Rosa opened her mouth to argue, but before she could go on, Cassandra’s governess came hurrying up and Rosa had no choice but to join in the pleasantries as they took their leave, promising to meet soon, before Christmas, before the wedding for certain. The last thing Rosa saw was Cassie’s pale little face in the window of the Knyvet carriage, above their coat of arms.

On the drive home she thought of Sebastian’s mother, and of his father, who she had never met. And she thought of her own father, of his round jolly face, his soft beard, the way his eyes twinkled beneath his top hat when he came home on winter nights. He had loved her – he had made her feel safe. There were very few people she could say that about, in her life. Except, perhaps, Luke.

And now they were both gone.

‘Tea!’ Mama said to James as they climbed the last few weary steps to the front hall. ‘And biscuits. And please tell the maid to see to the fire in the drawing room.’

‘Begging your pardon, madam, the fire is banked already. Mr Knyvet is waiting in there.’

‘Mr Knyvet?’ Mama dropped her packages on the hall table and rushed to the mirror to pull off her hat and adjust her hair. Then she turned to Rosa. ‘Oh, you’re a disgrace, Rosa. Trying to tame your hair is like trying to comb an – an octopus. Or a hedgehog.’

‘Mama!’ Rosa shrugged away from her mother’s pinching fingers. ‘I’m sure Sebastian doesn’t care about my hair.’

‘Sebastian will no doubt expect his wife to be impeccably groomed, as he is himself,’ Mama said sharply, but she let go and Rosa entered the drawing room.

Sebastian had his back to the door, staring into the roaring fire. Rosa felt its warmth on her face and wondered again at the change in their fortunes wrought overnight by that one simple word: yes. Where a few weeks ago there would have been meagre sticks and a few chips of coal, now the fire leapt and danced in the wide grate, its heat reaching every corner of the long room.

Her fingers hurt, the heat of the fire thawing them too fast for comfort, and she felt suddenly small and mean and full of self-hate. Sebastian’s name had brought all this. The logs in the grate, the parcels in the hall, the joint they would eat tonight. And she could not love him for it.

‘Sebastian,’ she said softly, and he turned.

‘My darling.’ He came across the room and took her face in his hands, tilting it up so that he could kiss her mouth. Her lips were cold from the street and his mouth felt feverishly hot against hers. She felt his tongue against her teeth and pulled away, and his lips curved in a thin, lazy smile.

‘Still playing the nun, Rosa?’

‘We’re not yet married. Mama is outside the door.’

‘Your mama is so delighted with our engagement that she wouldn’t care if I took you here on this rug.’

Rosa felt her face flush scarlet. For a minute she couldn’t speak. It was not just the crudity, but the fact that it was so close to being true, that robbed her of the power to reply.

‘Oh, Rosa!’ He kissed her again, but paternally this time on the forehead. ‘Your name was perfect – clairvoyant. You flush like a newly opened rose. I adore to shock you just to see the blush on your cheek – but you really shouldn’t make it so easy. Sit down, my darling, you look exhausted. Have you been wedding shopping?’

‘Yes,’ she said mechanically. It was almost true, Mama and Clemency had been wedding shopping, after all. Then she remembered her manners. ‘Sebastian, I was so sorry to hear about your father. What happened?’

‘An accident.’ Sebastian spoke shortly. ‘He had been working on an experiment, a sort of . . . transfusion.’

‘I don’t understand.’

‘Nor do I, completely. But it seems that there is a new machine that can extract –’ he glanced at the doorway, checking that they were alone, and lowered his voice ‘– it can extract the magic from one person and inject it into another, giving them strength and power beyond their own abilities. They had refined the process using prisoners, condemned men, you understand. Their success was mixed but at last they came to believe they understood the matching process. It seems that they were wrong.’

‘But was he mad?’ Rosa sank on to on the sofa. ‘What was he thinking, a Chair of the Ealdwitan to risk his life in an unproven experiment?’

‘Perhaps he was mad, yes.’ Sebastian’s face was hard. ‘The quest for power is a kind of madness of its own. My father was unsparing of others, but also of himself. He was not the only person to die in pursuit of this.’

‘But why do it at all?’

‘There are others, overseas, who are developing the same techniques. We cannot risk leaving this power in their hands alone.’

‘God in Heaven.’ Rosa put her face in her hands. When Clemency had shaken her head and refused to discuss Philip’s work at the Ealdwitan she had thought it was because it must be boring, political. Not this. Not this mad quest for power and domination.

‘So . . . what now?’ she managed. ‘Will you be Chair?’

‘Yes. I’m afraid our wedding must be postponed until that is ratified. It means yet more delays, on top of my father’s funeral. Do you mind?’

Mind? She almost laughed.

‘No, I don’t mind. I mean – I understand. This is more important.’

He took her hands and began pulling off her gloves and kissing her fingers one by one. At last he kissed the great stone that burnt on her left hand.

‘I mind,’ he said huskily, his soft, rough voice sending a shiver down her spine. ‘I cannot wait until you are mine, in name and body, in every way imaginable.’

She did not answer, but only stared into the fire. There was a sound at the door and Mama entered. She laughed at the sight of Rosa’s hand in Sebastian’s, and Rosa snatched it away.

‘Forgive me for disturbing you, my dear lovebirds, but I came to ask if you would stay for tea, or perhaps even dinner, Mr Knyvet? Please do not stand on ceremony here; we are all family now, or almost.’

‘Alas, I cannot.’ Sebastian stood and bowed. ‘I have to go to Spitalfields, to try to sort matters out at the factory and the soup kitchen. You cannot imagine the mountain of administration my father’s death has caused.’

Spitalfields. The word gave Rosa a pang, like a sudden stitch in her side. She shut her eyes for a moment, trying not to let Sebastian see.

‘Then let me ask James to bring your hat and coat,’ Mama was saying. She rang the bell and James appeared. As Mama gave the order, Rosa turned to Sebastian. She spoke quickly, before she could think better of it.

‘Sebastian, won’t you take me with you?’

‘Where, darling?’

‘To the East End.’ She could not bring herself to say ‘to Spitalfields’. It was too close to saying ‘to Luke’. She would never see him, she knew it. The East End was teeming, sprawling, filled with London-born and immigrants, sailors and natives, merchants, manufacturers and itinerant labourers. There was no hope of finding one face among the throng – and he would not recognize her if they did meet. But at least it would be something – something more worthy than endlessly shopping with Clemency and Mama – that could be of real value to others. She thought of Luke’s friend, the skinny girl with hungry eyes too large for her face that she had sent to the Knyvets’ soup kitchens. ‘Listen, if I’m to become part of your family, I want to understand your businesses, your family’s philanthropy. Please – take me to the factories, to the soup kitchens. Perhaps I can help in some way.’

‘It is no place for a lady!’ Mama exclaimed.

‘That’s not true! Think of Lady Burdett-Coutts, Mama! Think of all she has done for the poor.’

‘Her interests are fallen women,’ Mama said tartly. ‘Hardly suitable for an unmarried girl of sixteen, Rosa!’

‘Please . . .’ Rosa turned to Sebastian, knowing it didn’t matter what Mama thought – if Sebastian agreed, Mama would acquiesce. ‘Please take me. I’m not cut out for a life of idleness and shopping. I want to do something, something to occupy myself. I know I can’t do much now, as an unmarried girl, but if I understand your family’s concerns then perhaps, after we are married . . . ?’

Sebastian took his coat and hat from James and put them on. He looked as if he were thinking. At last he spoke.