‘She works that horse too hard,’ William said.

‘I know.’ Luke rubbed his hands on his apron and turned back to the yard, ready for the day’s work. ‘I told her. But she works herself too hard and all.’

‘Did you charge her for the shoe?’

‘She’ll pay.’

‘No she won’t. You’re too soft-hearted.’

‘It’s not her fault. How’s she supposed to make a girl’s wage stretch to cover four mouths?’

‘I know, I know.’ William shook his head. ‘And her dad’s as useless as they come.’

‘He’s not long for this world, neither.’ Luke thought of the last time he’d seen Mr Sykes, sitting in his own piss in a corner of the hovel Minna called home, with his youngest two running around his feet, noticed only when they came too close to knocking over his bottle.

‘There’s many a better man than Nick Sykes rotted their brain with moonshine,’ William said. ‘She should sell that horse, get a donkey, use the money for the little’uns.’

‘She never will,’ Luke said with certainty. ‘You know Bess was her dad’s, back when he were a drayman. In Minna’s eyes she’s just borrowing Bess until he’s fit to work again.’

‘And that’ll be sometime west of never,’ William Lexton said with a sigh. Then he turned to the forge. ‘Come on now, enough gabbing. We’ve got work to do before I lose you.’

‘Lose me?’

‘Well, you can’t work here and do your task for the Brotherhood, can you?’

‘But—’

‘It’s not going to be easy, Luke. I tried to tell you last night, but you were too full of yourself to listen. No, no –’ he held up a hand as Luke began to protest ‘– I know. And I would have been the same at your age. But these are no ordinary witches, Luke. John Leadingham’s told me a bit about this family. The son’s thick as thieves with Sebastian Knyvet. They went to school together, spent half their boyhood round at each other’s houses, from what I can make out.’

‘And who’s this Knyvet bloke then?’

‘Who’s . . . ?’ His uncle gave him a look that mingled surprise and irritation. ‘Do you listen to anything I tell you? I tried to tell you all this last night. He’s one of the Ealdwitan. And you know who they are, don’t you?’

Yes. Luke knew who they were. The witch elite of England. The ruling council. If they only ruled the witches – that would be one thing. But their tentacles reached into every place of power in the land. Half the MPs in the House of Commons were Ealdwitan and a good measure of the peers in the House of Lords too. If there was a prospect of money or power they were there, to get their share of the pie, and more.

‘Aloysius Knyvet is one of the Chairs who head the Ealdwitan. Sebastian’s his eldest son. Now do you see why I said this was a fool’s errand?’

‘So they’ve got friends in high places.’ Luke shrugged. ‘They’ve still got skin that burns and flesh that bleeds, don’t they?’

‘Yes, but it’s getting to that skin or that flesh. And that’s easier said than done. At least you’ve got an advantage, though I don’t know how far it’ll help. You’ll have to be careful not to let on. If you once show what you are, that you know what they are . . .’

Luke turned away. He hated being reminded of what he was. A witch-finder.

No one knew where the ability had come from. William thought he had been born with it, and that perhaps Luke’s father had had the same ability but had never known it, or had kept it secret through fear. John Leadingham thought that it had been gifted to Luke the night he watched his parents die – that that one searing experience had burnt the gift into him, so that never again could he look on a witch and see an ordinary man or woman. Except, as Luke himself often wondered, he could not be the only person to have seen a witch, nor even the only person to have seen a witch kill. But he was, as far as he’d ever heard, the only person who saw them for what they were, as clear as others saw black from white. Even in the street he could see them, dressed like ordinary people, walking and talking like ordinary people but with their witchcraft shimmering and crackling around them, marking them out as clear as night from day.

Sometimes it was nothing but a faint gleam, soft as a dying ember. Other times it was bright; bright as a gas-lamp, bright as a flame. When they cast a spell the magic flared and waxed, as the candlelight guttered and waxed in the draught from the door. Then it waned, fading back, leaving them dimmer than before.

It had taken him a long while to understand that others did not see witches as he did. It had taken the Malleus even longer to believe what they had found – a child who could see witchcraft – no need to test and prod and accuse. His word alone was enough.

‘We’ll have to get you inside the household somehow. A servant or summat. John Leadingham’s looking into it.’

‘I can’t be a servant!’ Luke said, horrified.

‘What! Too proud to sweep a floor?’

‘No! I don’t mean that. I mean, I wouldn’t know how! How could I be a footman in some great house? I wouldn’t know the first thing about what to do – I’d get the sack before my feet had touched the ground.’

‘A footman no, but there might be something else. You’re too old for a boot-boy, but a garden hand maybe. I don’t know about London, but John says they’ve got a great rambling place in the country with a hundred acres and more. There must be work for a man there.’

‘What if they’re not in the country? Don’t the gentry come up to town in the autumn?’

‘I don’t know.’ William shook his head. ‘You’re asking the wrong bloke, Luke. But where there’s a will, there’s a way. If there’s a chink in their armour, John Leadingham’s the man to find it. By fair means or foul, we’ll get you into that house. And after that . . .’

After that, it would be up to Luke.

‘I’ve got a plan.’ John Leadingham tapped the side of his nose as they walked down the narrow alleys, tall warehouses towering either side of them, their top storeys disappearing into the shrouding murk. Luke could hear the lap of the Thames on the mudflats and the bellow of a horn as a ship made its way downriver in the thick yellow fog.

‘What is it?’ Luke asked, but John shook his head.

‘Ask me no questions, young Luke. You’ll know soon enough, but for the moment I’m still working out some of the finer details. Now . . .’ He stopped at one of the furthest warehouses – a tumbledown wooden structure that looked as if it might just slide into the Thames mud at any moment – and drew a key from his pocket. ‘You’re not squeamish of a little blood, are you?’

‘No,’ Luke said, but his stomach twisted, wondering what awaited him inside the warehouse. He thought of the nights when William came home with blood on his hands and shook his head, pale-faced, when Luke asked him questions about what he’d done. Would it be a witch, captive, awaiting trial?

The door swung wide and the stench of blood that flooded out made him take an involuntary step back, but John Leadingham strode inside as if he hadn’t noticed.

Luke found himself standing tense, his muscles ready to fight or fly, as the gas-lights flared out across the warehouse. But then he laughed, the noise sounding strange and light with relief in his own ears.

‘Pigs!’

Carcasses swung from hooks in the beams and there were bones stacked by the door out to the wharf. And not just pigs, he saw. There were sides of beef over the far side, and sheep too, stripped of their wool and skinned, with sharp grinning teeth and staring, round eyes.

‘Well, what else did you expect? I’m a butcher, ain’t I?’ John swung the door shut with a dull thud of rotten wood and took off his coat. ‘It’s an abattoir.’

‘Why’ve you brought me here?’

‘Because I’m not sending a sheep to the slaughter – pardon the pun.’ He pulled on a bloodstained apron and picked up a knife. ‘You can fight, Luke, I’ve seen it. Even better if you’ve got a bit of beer in you. But you can’t kill. That’s a different skill completely – and one you need to learn, and fast. I’m not saying you should gut this girl like a stuck pig, of course not. I’m hoping you’ll get the job done a good deal more subtly than that. But the fact is, you may find yourself in a tight corner, and carrying a knife and knowing where to stick it can take you a long way.’

He threw an apron at Luke and then a knife, hilt first. Luke fumbled the catch and cut himself across the palm, and John Leadingham grinned.

‘Lesson one – make sure you end up on the right end. Now . . .’ He pointed at the corpse of a pig, swinging gently on a butcher’s hook driven in under its chin. ‘This is a man. Where are you going to stick that thing?’

For the next three hours Luke worked harder than he’d done in a long time, and by the time Leadingham let him stop he was sweating, gasping and spattered with gore, the knife slipping in his bloodstained hand.

His head was spinning with all the new information – where to nick an artery, where to slice a tendon. What would incapacitate a witch, and what would merely slow him or her down while they healed themselves. And all the time, as John Leadingham barked out, ‘Femoral artery, kidney, achilles,’ Luke stabbed the pig and yanked out the knife.

‘Don’t think strength can help you. If they clock what you are – carotid artery – your best bet is to get their trust, get in close, then when they least expect it, strike. Spleen! Stick ’em as hard and fast as you can, and get out. Pulmonary artery! No, not there, you dolt. That won’t do more than give them a nasty scar and they’ll be up and at you before you can say “Spring-Heeled Jack”. Here . . .’ He stabbed the knife in between the ribs with a grunt and a crunch that made Luke’s stomach turn. ‘You’ve got to remember, a witch’s magic lies in their strength, and their strength lies in their blood. Draw off enough blood and you’ll weaken their magic too. Right kidney! Good, good man. Now, go for the tendons behind the knee – no, don’t stab, slice. That’s right. Brace their weight against yourself to get a purchase – and remember they’ll likely be slippery with blood.’

At last he stopped and took Luke’s shoulder, turning him panting and red-faced to look at him.

‘This is easy enough with a dead pig that doesn’t dodge or strike back or cry with pain. Now I want you to do the same thing, but imagine this pig is a girl – a girl who cries out as you come at her with the knife and tries to get away.’

‘You want me to imagine this pig is a girl?’ In spite of himself, Luke stifled a smile. His chest was rising and falling, and his limbs felt like glue, but the idea still made him want to laugh. ‘How desperate d’you think I am?’

‘Just try it.’

‘If you say so.’ It was hard to think of anything but the fat, bristly carcass swinging to and fro, but Luke shut his eyes and pictured a girl hanging where the pig was, a blonde maybe like Phoebe, her blue eyes wide with horror as he came towards her with the knife. ‘All right, I’m picturing it.’

‘All right then. Go. Aorta!’

Luke opened his eyes and lunged, knife outstretched, for the pig’s throat – and behind him a voice screamed, ‘No! Oh God, spare me!’

Luke stumbled, slipping in the blood, and the knife fell from his hand as he slammed against the pig, grabbing at its cold, clammy flanks to try to steady himself.

‘What the hell?’

John took a step forward out of the shadows and his face was grim.

‘That was all it took, was it? Me screaming like a girl – and a bloody poor imitation, if I do say so myself – and you were tripping over your own feet and turning to jelly?’

‘Damn.‘ Luke could have kicked himself. Damn.

‘You think you’re a man, Luke, and you are – but it’ll take more than a man to kill this girl. It’ll take a Brother. One of the Malleus. The test of the knife, the test of fire – they’re nothing to this. Because with this you have to defeat yourself, as well as the witch, d’you understand? They’ll use every weapon they can against you – they’ll weep, they’ll plead, just as they’ll fight and lame and maim. If you’re afraid—’

‘I’m not afraid,’ Luke broke in roughly. John put his hand on his shoulder.

‘I didn’t say you were, son. But if you are afraid, they’ll see that and they’ll turn your fear against you. And if you have a kind heart, they’ll turn that against you too. So you must have no heart, understood? You must have no fear. You must be nothing but the hammer.’

4

‘There’s worse fates than marrying for money, Rose.’ Clemency put a sugared plum in her mouth and smiled, her plump cheeks dimpling, her lips sticky with syrup. ‘I should know. And better a rich wife than a poor spinster.’