The man wrapped a cloth around his hand, picked up the handle resting on the hearth and drew the glowing tip out of the fire. It was a brand: he’d seen one often enough to recognize it. Luke’s uncle used them on horses and sometimes cattle, if their owners needed them to be marked. He’d even branded a few animals himself, when his uncle was busy, and he’d always winced at their pain and their bellowing cries, but never thought that one day . . .

The end glowed so bright he could not see the design, only the heat that shimmered from it, making the air ripple and waver. Then the man thrust it back into the heart of the fire and spoke.

‘Take off your shirt.’

Luke swallowed against the dryness in his throat and he began to fumble with the buttons of his shirt. The men watched, their eyes glinting in the firelight as his reluctant fingers loosened one button, then two, then another, and another, until his shirt hung loose and he could feel the heat of the fire on his naked chest and belly. Blood was already crusting around the cut he’d made, the trail down his side turning black and cracked. He took off the shirt and laid it on the floor at his feet.

‘This test is a test of endurance and silence. You must not flinch. You must not cry out. By enduring this test in silence you show that your loyalty to the Brotherhood may be tested, but you will not betray them by any cry or word. Do you understand?’

Luke nodded, not sure that his voice would obey him, but the man shook his head.

‘Speak, Luke. Do you understand?’

‘I understand,’ he said hoarsely.

‘Then kneel and hold fast to the chair.’

Luke knelt, holding on to the back of the chair, feeling his breath coming fast and his heart racing beneath his ribs as if he might be sick. One of the other men held on to the seat of the chair so that it wouldn’t rock or fall if he flinched or fell himself. Luke heard the whisper of ash as the man took the brand from the fire, and his blood sang in his ears, a strange, fierce, fearful song.

‘Hold fast, Luke Lexton,’ said the voice.

Then there was a hiss and a heat against his shoulder. For a moment there was no pain and he thought it was all a trick, as the knife had been. But then a roaring, tearing anguish began to engulf his skin and his muscles, until it seemed as if even the bones of his shoulder itself were burning. A great bellow of agony rose up from his guts and he almost cried out, but just in time he remembered his promise of silence and he gripped on to the struts of the chair and bit into his own forearm so that no sound escaped but his tearing, whimpering, ragged breaths.

Beneath his closed lids, constellations of pain exploded and spun and his blood roared in his ears. He wanted nothing more than to beg for it to stop, to scream for water, for pity, for anything.

The circle of masks was completely silent, listening to his struggle, listening for any cry. Then, after what seemed an age, the first man spoke.

‘Well done, Luke Lexton. You’ve passed the trial by fire.’

There was a hiss of breaths released around the room and Luke gave a sobbing groan.

‘Get something for the burn,’ the man said, and one of the masked men came hurrying forward with a pot of grease, like the one Luke’s uncle used when he burnt himself at the forge. He felt his shoulder smeared with the ointment and then hands helped him to sit, pulling him to a settle, dressing the burn with a clean cloth.

‘You’ll have a wound for a few days,’ said the man. ‘And then a mark, as we all do. As best we know, the meaning of this mark is not known to any outsiders. We show it to none but our wives – and they mustn’t know what it signifies. D’you understand?’

This time Luke could not speak, he only nodded, and the man seemed satisfied.

‘Good. Good man, Luke Lexton.’

They passed him his shirt and, with their help, he struggled into it, feeling the bandage over his shoulder grate and move as the rough cloth jostled the dressing. There were teeth marks in his arm. He’d not broken the skin, but there would be a welt there for a while.

Someone passed him a half-drunk tankard and he drained it, before he realized that it was not beer, but gin. It burnt his gullet and then smouldered in his gut, and he half sat, half lay across the settle in front of the fire, feeling the sick cold in his limbs subside a little with the warmth of the fire and the warmth of the gin.

‘And now, for the last trial – the trial of the hammer.’

‘Wait,’ said a voice from beneath a hood, and for the first time Luke recognized his uncle’s voice. ‘Give him a minute, Brother. He’s in no fit state—’

‘He’s conscious,’ said the man in the gown sternly. ‘He knows his own mind and can plead his own case. Luke Lexton, are you fit to continue?’

Coward, whispered the voice.

Luke was sick and sweating, but he managed to sit up straighter. He wasn’t about to back down now and shame himself and his uncle and the memory of his parents. He nodded.

‘I can carry on.’ His voice was strange in his own ears. His throat felt tender and raw, as if he had screamed himself hoarse, though he knew full well he’d not made a sound except for shameful pup-like whimpers. He wondered if his uncle had been this weak, or if he’d borne the brand in proud silence, and he gritted his teeth and forced himself fully upright. ‘I can carry on.’

‘Good man,’ said the man in the gown. ‘Now, this last trial is different. All we require of you tonight is that you accept the task and undertake to do it to the best of your abilities, or die in the attempt. Tonight the moon is full – when the full moon rises again, either they must be dead, or you. D’you understand?’

‘Yes,’ said Luke, though he did not.

‘Bring out the book,’ said the man. There was a rustle at the back of the room and an old masked man limped slowly forward, a huge brass-bound book in his hands. The man in the gown fitted a brass key to the lock and opened the book.

Inside was page after page after page of closely written names, some with a line through, some scratched out so harshly that the paper was rough and hollow.

‘This book contains the name of every witch known to this organization – some of them listed thanks to you, Luke – and every one we’ve sworn to hunt down and kill. The men and women named here have poisoned our brothers and sisters, enslaved them, enchanted them, even killed them. Every one has a heart as black as pitch and it is our sworn duty not to rest until London is wiped clean of their kind. After the trial of the knife and the trial by fire, we ask our Brothers for one more trial to prove their worth – the trial of the hammer: they must pick a name from the book and kill that witch. Do you understand?’

‘Yes,’ said Luke. And now he did. He stared at the list of names, the faded, scratched handwriting swimming before his eyes. ‘What of the ones who’re scratched out?’ he asked.

‘They’re the ones your Brothers have killed before you.’

‘How do I choose?’

‘We let God choose. We bind your eyes, give you a pin. God will guide you to the name. Are you ready?’

‘I’m ready,’ Luke said. He sat motionless while they tied a cloth over his eyes and then pushed a pin was pushed between his fingers. Then he felt for the stiff pages of the book beneath his other hand.

He turned the pages slowly, carefully, blindly. There was only one thing in his mind: a figure. A figure he had glimpsed by firelight long ago and the tall shadow it cast on the bedroom wall behind it. It was almost fifteen years since he had seen its shape, but it was still burnt into his mind, and his eye, and all of his nightmares.

This is for my ma, he thought, as his fingers ran down the list, as if touch could guide him to the right name. This is for my pa, as he came to a stop, the pin poised in his hand. Please God, let it be him. Let it be the right one.

He stabbed with the pin, feeling it pierce the page deep, deep, as he ground it into the book with all the strength of his hatred.

‘He’s chosen.’ The man’s voice rang out in the small room. ‘Let it be witnessed; he’s chosen.’

Luke fumbled with the bandage and opened his eyes, blinking, to the firelight and the circle of faces. Then he bent his head to the book, to see what name lay skewered by his pin.

‘Rosamund Greenwood,’ he read aloud, with a stab of fury. A woman. He knew nothing about her, except that she was a witch. A witch, but not the one he’d wanted, and for that alone he hated her, as if the rest wasn’t reason enough. She’d robbed him of avenging his father and mother and—

‘No.’ A voice was rising from the back of the room in panic. ‘No, no, no. He must choose again.’

‘Brother.’ The gowned man held up a hand. ‘You know the rules . . .’

‘No!’ The speaker tore off his mask and Luke saw his uncle standing there, his face flushed with the fire. ‘You must be mad, John! Her brother’s Alexis Greenwood, thick as thieves with the Knyvets, or so they say. To send a green boy up against witches like that—’

‘You know the rules.’ The gowned man spoke wearily but firmly. ‘Put your mask back on, Brother, or you’ll be thrown from the meeting.’

‘He’ll be killed!’ William roared.

‘She’s nowt but a sixteen-year-old girl, William,’ another voice tried to put in. ‘It coulda bin worse—’

‘Worse? Only if she’d picked Knyvet himself, or another of the Ealdwitan! And then I might as well cut his head from his shoulders right here and save us the trouble of fetching his body. Let him choose again, I say!’

‘No.’ John pulled off his own mask and faced William. His face was both angry and sad. ‘The rules are the rules, William. We can’t pick and choose for our own, you know that as well as I. God knows, we’ve had hard choices before – Bates, Jack Almond, young Tom Simmonds. We’ve lost Brothers and mourned ’em but—’

‘Not in a lost cause!’ William’s voice broke, and he took John by the shoulders. ‘We’ve lost fights, lost men, I know that as well as you. But this is a lamb to the slaughter. Do not do this, John. You’re a good man – better than this.’

‘Hey,’ Luke said from where he sat. They took no notice of him. He stood and said louder, ‘Uncle! William!’

Two faces, red in the firelight, turned to look at him. Luke thought they’d almost forgotten he was there.

‘It’s my choice,’ he said bitterly. ‘Mine. And I choose to take the task. A sixteen-year-old girl, you said – and you think I’m a lamb to the slaughter?’

‘You don’t understand, boy—’ William began, but Luke broke in. His fists were clenched so that his nails made half-moons on the skin of his palms.

‘I understand. I understand that every other man here’s done as I’m being asked to do, and none of them backed down. Don’t take away that right from me. I’ll not have men say I was too frightened to face a girl fresh out of the schoolroom.’

‘Luke . . .’ William put out a pleading hand, but Luke turned away from his uncle towards John Leadingham.

‘I accept the task. I’ll kill the girl. And there’s an end.’

2

‘Shh, not on the bed, Belle.’ Rosa pushed at the little dog and it thudded sulkily to the floor and shuffled over to the window seat, where it circled busily until it settled itself in a neat ring, tail over its nose.

‘Watch out if Mama catches you,’ Rosa said warningly. Belle let out a little whine of contentment and closed her eyes, and Rosa turned back to her sketch book and the view from the window, over the rooftops of Knightsbridge. The fog was closing in and she could just see, above the yellow shifting sea, dark rooftops and the tips of chimneys, each trickling the coal smoke that made London’s pea-soupers so deadly. Not for the first time, Rosa was glad that her bedroom was on the top floor of their tall house. Only the maids slept higher than she, in the attics, beneath the slates.

She swapped pencils for a sharper point and began to fill in the fine detail of the slates and chimneys.

‘Down, you god-damn mutt!’ The voice came like the crack of a whip.

Rosa jumped as hard as the little dog. Belle leapt to the floor and scurried under the bed, and Rosa’s pencil clattered to the floor. She knew who it was, of course, even before she caught sight of him standing in the doorway. He was dressed in riding clothes, his polished boots spattered with mud, and there was a crop in his hand. His face was red with exercise – as red as his hair.