‘Especially not to Sebastian. You must promise me you will never mention that you have seen her.’

‘I promise.’ Her head was aching and her knees shook as she stood upright. ‘But, Cassie, why?’

But Cassie said nothing, and Rosa found that it took all her strength and concentration to put one foot in front of the other.

It was only later, much later, in her room that she closed her eyes on the pillow, and that strange gaunt face floated in front of her vision again. What was wrong with Cassie’s mother? Was Sebastian so ashamed that he could not bear to have her talked about?

She was too exhausted to think about it for long. Instead she drifted into a troubled sleep, with dreams haunted by pounding hooves, Luke’s sobbing pleas, and a strange wild-haired witch with Sebastian’s eyes.

Luke was walking slowly back from the stables when he heard horses’ hooves. He looked up. Alexis and Sebastian were trotting into the yard. When they saw Luke both changed direction to come across to him. Alexis had his crop in his hand, twitching against his thigh. Sebastian had a bloody fox foot dangling from his saddlebag. They were both keyed up from the hunt, full of triumph and arrogance and a sense of their own potency. Luke felt suddenly very weary with the knowledge of what was about to happen.

Every part of him hurt. His shoulder ached from where he had wrenched it trying to heave Cherry off Rosa’s body. His back ached from carrying her all that long trek up to the house. Most of all his heart ached, at the knowledge of what he’d done, what he faced back in London . . .

He did not feel fear at the sight of Alexis and Sebastian – he felt only an intense weariness at the unjustness of it all. He could have killed Alexis. He could have killed him in cold blood and felt he’d done the world a service. He could have killed Sebastian – not with joy, but with a grim sense of right. Why couldn’t he have drawn their names? Why Rosa and not them?

He turned away.

‘Hi!’ Alexis’ shout rang across the yard. ‘You. Where d’you think you’re going, eh?’

Luke kept walking.

‘I said stop!’ Alexis bellowed furiously and, to his shock and fury, Luke felt his feet drag on the ground, as if invisible weights had suddenly attached themselves to his boots. He gritted his teeth and pulled against the heaviness – but before he could free himself he heard Sebastian’s low, angry, ‘For God’s sake, Greenwood.’

The pull loosed abruptly, but he would not give them the satisfaction of seeing him flee. Not now. He shoved his hands in his pockets and turned to face them.

‘What the hell are you playing at?’ Alexis snarled as Brimstone came level with Luke. He flicked out with his whip, catching Luke painfully across the ear. ‘First you disappear from the hunt and then saunter back here like I’ve nothing better to do than wait on your convenience. Where the hell were you?’ Luke bit his lip, and Alexis shouted out, ‘Answer me, damn you!’ The crop flicked again and Luke felt a sting on his cheek. When he put his hand up there was blood.

‘Saving your sister’s life,’ he ground out, hating them both with every ounce of flesh and blood and bone in his body.

‘What?’ It was Sebastian, not Alexis, who slid off his horse to stand level with Luke. ‘What did you say?’

‘You heard me. And you heard me on the ridge, didn’t you? Calling?’

Sebastian went very still, as still as stone.

‘That’s right,’ Luke said. ‘I was calling for help. The bridge gave way. Cherry fell. She’s dead, impaled on one of the bridge posts. Rosa was underneath when she fell.’

‘My God.’ There was no trace of emotion in Sebastian’s face, his eyes were as dead and cold as ever they had been. But his face had gone white, with two spots of colour high on the cheekbones. A splatter of mud stood out black against his pale skin. ‘Is this true?’

‘What d’you mean, saved her life?’ Alexis blustered. ‘Stood by while she scrambled out, I’ll warrant. And she’s Miss Greenwood to you, you lying—’

‘Shut up,’ Luke snarled. He didn’t care if he was sacked. His mission was over. Everything was over. ‘Speak to her yourself if you don’t believe me.’

Then he walked away, trying to keep his breathing even and his fury inside. He half expected to hear hooves behind him and turn to meet Alexis’ crop, or his fist. He half wanted to. It would have been a relief to draw back his fist and let fly – there would have been a grim satisfaction in hearing the smack of bone against bone.

But there was no sound. Only the crunch of gravel beneath his own feet until he reached the side door and was able to slip inside, out of sight. He walked slowly up the back stairs to his little room. Thank God it was empty. He lay face down on the thin horsehair mattress and the tears came at last.

Rosa opened her eyes. There was a tapping coming from somewhere. For a moment she was disoriented – quite unable to work out where she was. The room was warm and dim, full of looming shadows. Thick velvet drapes shut out the day and the only light was from the flicker of a log fire. There were goosefeather pillows beneath her cheek and a satin eiderdown across the bed.

Then she remembered. She was at Southing. Sebastian’s house. Cherry was dead. And Luke had seen things no outwith should ever have witnessed.

She closed her eyes, shutting out the sight of Luke as she had left him, white and exhausted and shocked by all that had happened.

Then the tap came again.

‘Come in,’ she called.

The door opened and a small, pale face peered round.

‘Cassie!’ Rosa jumped out of bed and ran across the room. ‘Thank you – oh, thank you. I never had the chance to say. Is your mother—’

‘I haven’t much time.’ Cassie spoke quickly and quietly. ‘I’m supposed to be practising the piano with my governess. It’s about your groom . . .’

‘Yes.’

‘He’s an outwith.’ She said it flatly, not a question but a statement.

Rosa nodded, forgetting Cassandra couldn’t see and then said hastily, ‘I mean, yes. Yes he is.’

‘And he saw Mama.’

‘Yes.’

‘Rosa – I wouldn’t ask this if it were someone else – but Mama, she . . . she’s not well.’ She stopped, twisting a handkerchief in her small white fingers. ‘No one must know what she did. No one must ever know – least of all Sebastian. We need to make Luke forget.’

Rosa said nothing. She bit her lip, thinking of Alexis and Becky, thinking of the power they held over the outwiths who shared their lives.

‘Do you understand what I’m saying?’ Cassie asked.

‘Yes,’ Rosa said reluctantly. ‘Yes, I understand. But, Cassie – what’s wrong with her? Why mustn’t Sebastian know?’

‘She’s mad. She’s always been mad, since I was born. Since before, perhaps. They say she’s dangerous – that she must be confined for her own safety. Father would be terribly angry if he knew that she had come down. Believe me, Rosa, you do not want to encounter my father’s anger.’

Rosa bit her lip. She had seen Sebastian’s fury. She could imagine his father’s.

‘But it’s not just Mama,’ Cassie pressed on. ‘It’s all of us. He knows. He has to un-know.’

‘Yes,’ Rosa whispered. It was not fair. Luke had saved her life and this was his reward – for her to reach inside his head and steal her memories. She had never wiped a memory before, but she had watched Alexis do it to Becky often enough. A cup of wine, steeped with rosemary for remembrance. The victim drank the wine, while you told them what you wanted them to forget, then whispered the incantation and burnt the herbs, burning away the memories.

‘If Sebastian finds out what Luke saw – well, Luke’s life wouldn’t be worth a farthing. I have the wine,’ she pulled a bottle out from a pocket in her skirts, ‘but without sight I can’t find him in the stables – and I doubt he would drink wine from a strange witch anyway.’

‘No,’ Rosa said. She gave a sigh as heavy as her heart. ‘It must be me. I can see that.’

‘And it must be tonight,’ Cassie said. ‘Are you strong enough?’

She didn’t know.

It was dark when Rosa let herself out into the yard. She had waited until the house party was having dinner, the time when all guests and most of the servants would be safely occupied. A maid had bought her up a tray of suitably invalid food – creamed chicken, white bread, beef tea. It had taken only a moment to choke it down, put a locking spell on the door and creep out into the night with her oldest cloak covering her nightgown and her tell-tale hair.

Now, as she tiptoed across the moonlit stable yard, she wondered what she would do if Luke were not in the stables, if he had gone up to his room already, or into dinner. How would she find him in this huge, rambling warren of a house?

But when she opened the door to the stables he was there, wearily sweeping out Cherry’s empty stall by the light of a storm-lantern hanging from the wall.

The sight brought tears rushing to the back of her throat and eyes, but she blinked them away angrily. She could not grieve for Cherry – not yet. When this was over, when she was back in London and could think again, perhaps. But not now.

‘Luke,’ she whispered.

He looked up and, for an instant, his expression was bewildered. Then he saw her looking round the stable door and his face became hard. He glanced left and right and hurried across.

‘What are you doing here?’ His voice was low and angry.

‘I – I came to thank you.’ It was true. It was not the whole truth. ‘Can you talk?’

‘No.’ He glanced over his shoulder. ‘You shouldn’t be here, Miss Greenwood.’