Grey rose himself, perforce, and took Miss Nancy’s hand, bowing over it.

‘Your servant, Miss Twelvetrees,’ he said. ‘I hope—’

‘We know,’ she said, staring at him from large, suddenly tear-filled eyes. ‘Do you hear me? We know.’ Then she was gone, the sound of her unsteady steps a ragged drumbeat on the parquet floor.

There was a brief, awkward silence between the two men. Grey cleared his throat just as Philip Twelvetrees coughed.

‘Didn’t really like cousin Edward,’ he said.

‘Oh,’ said Grey.

They walked together to the yard where Grey’s horse browsed under a tree, its sides streaked with parrot-droppings.

‘Don’t mind Nancy, will you?’ Twelvetrees said quietly, not looking at him. ‘She had . . . a disappointment, in London. I thought she might get over it more easily here, but— well, I made a mistake, and it’s not easy to unmake.’ He sighed, and Grey had a sudden strong urge to pat him sympathetically on the back.

Instead, he made an indeterminate noise in his throat, nodded, and mounted.

‘The troops will be here the day after tomorrow, sir,’ he said. ‘You have my word upon it.’

Grey had intended to return to Spanish Town, but instead paused on the road, pulled out the chart Dawes had given him, and calculated the distance to Rose Hall. It would mean camping on the mountain overnight, but they were prepared for that – and beyond the desirability of hearing at first-hand the details of a maroon attack, he was now more than curious to speak with Mrs Abernathy regarding zombies.

He called his aide, wrote out instructions for the dispatch of troops to Twelvetrees, then sent two men back to Spanish Town with the message, and sent two more on before, to discover a good campsite. They reached this as the sun was beginning to sink, glowing like a flaming pearl in a soft pink sky.

‘What is that?’ he asked, looking up abruptly from the cup of gunpowder tea Corporal Sansom had handed him. Sansom looked startled, too, and looked up the slope where the sound had come from.

‘Don’t know, sir,’ he said. ‘It sounds like a horn of some kind.’

It did. Not a trumpet, or anything of a standard military nature. Definitely a sound of human origin, though. The men stood quiet, waiting. A moment or two, and the sound came again.

‘That’s a different one,’ Sansom said, sounding alarmed. ‘It came from over there—’ pointing up the slope, ‘—didn’t it?’

‘Yes, it did,’ Grey said absently. ‘Hush!’

The first horn sounded again, a plaintive bleat almost lost in the noises of the birds settling for the night, and then fell silent.

Grey’s skin tingled, his senses alert. They were not alone in the jungle. Someone – someones – were out there in the oncoming night, signalling to each other. Quietly, he gave orders for the building of a hasty fortification, and the camp fell at once into the work of organising defence. The men with him were mostly veterans, and while wary, not at all panicked. Within a very short time, a redoubt of stone and brush had been thrown up, sentries posted in pairs around camp, and every man’s weapon was loaded and primed, ready for an attack.

Nothing came, though, and while the men lay on their arms all night, there was no further sign of human presence. Such presence was there, though; Grey could feel it. Them. Watching.

He ate his supper and sat with his back against an outcrop of rock, dagger in his belt and loaded musket to hand. Waiting.

But nothing happened, and the sun rose. They broke camp in an orderly fashion, and if horns sounded in the jungle, the sound was lost in the shriek and chatter of the birds.

He had never been in the presence of anyone who repelled him so acutely. He wondered why that was; there was nothing overtly ill-favoured or ugly about her. If anything, she was a handsome Scotchwoman of middle age, fair-haired and buxom. And yet, the widow Abernathy chilled him, despite the warmth of the air on the terrace where she had chosen to receive him at Rose Hall.

She was not dressed in mourning, he saw, nor did she make any obvious acknowledgement of the recent death of her husband. She wore white muslin, embroidered in blue about the hems and cuffs.

‘I understand that I must congratulate you upon your survival, madam,’ he said, taking the seat she gestured him to. It was a somewhat callous thing to say, but she looked hard as nails; he didn’t think it would upset her, and he was right.

‘Thank you,’ she said, leaning back in her own wicker chair and looking him frankly up and down in a way that he found unsettling. ‘It was bloody cold in that spring, I’ll tell ye that for nothing. Like to died myself, frozen right through.’

He inclined his head courteously.

‘I trust you suffered no lingering ill-effects from the experience? Beyond, of course, the lamentable death of your husband,’ he hurried to add.

She laughed coarsely.

‘Glad to get shot o’ the wicked sod.’

At a loss how to reply to this, Grey coughed and changed the subject.

‘I am told, madam, that you have an interest in some of the rituals practised by slaves.’

Her somewhat bleared green glance sharpened at that.

‘Who told you that?’

‘Miss Nancy Twelvetrees.’ There was no reason to keep the identity of his informant secret, after all.

‘Oh, wee Nancy, was it?’ She seemed amused by that, and shot him a sideways look. ‘I expect she liked you, no?’

He couldn’t see what Miss Twelvetrees’s opinion of him might have to do with the matter, and said so, politely. Mrs Abernathy merely smirked at that, waving a hand.

‘Aye, well. What is it ye want to know, then?’

‘I want to know how zombies are made.’

Shock wiped the smirk off her face, and she blinked at him stupidly for a moment, before picking up her glass and draining it.

‘Zombies,’ she said, and looked at him with a certain wary interest. ‘Why?’

He told her. From careless amusement, her attitude changed, interest sharpening. She made him repeat the story of his encounter with the thing in his room, asking sharp questions regarding its smell, particularly.

‘Decayed flesh,’ she said. ‘Ye’d ken what that smells like, would ye?’

It must have been her accent that brought back the battlefield at Culloden, and the stench of burning corpses. He shuddered, unable to stop himself.

‘Yes,’ he said abruptly. ‘Why?’

She pursed her lips in thought.

‘There are different ways to go about it, aye? One way is to give the afile powder to the person, wait until they drop, and then bury them atop a recent corpse. Ye just spread the earth lightly over them,’ she explained, catching his look. ‘And make sure to put leaves and sticks over the face afore sprinkling the earth, so as the person can still breathe. When the poison dissipates enough for them to move again, and sense things, they see they’re buried, they smell the reek, and so they ken they must be dead.’ She spoke as matter-of-factly as though she had been telling him her private receipt for apple pan-dowdy or treacle-cake. Weirdly enough, that steadied him, and he was able to speak past his revulsion, calmly.

‘Poison. That would be the afile powder? What sort of poison is it, do you know?’

Seeing the spark in her eye, he thanked the impulse that had led him to add ‘Do you know?’ to that question – for if not for pride, he thought she might not have told him. As it was, she shrugged and answered off-hand.

‘Oh . . . herbs. Ground bones – bits o’ other things. But the main thing, the one thing ye must have, is the liver of a fugu fish.’

He shook his head, not recognising the name. ‘Describe it, if you please.’ She did; from her description, he thought it must be one of the odd puffer-fish that blew themselves up like bladders if disturbed. He made a silent resolve never to eat one. In the course of the conversation, though, something was becoming apparent to him.

‘But what you are telling me – your pardon, madam – is that in fact a zombie is not a dead person at all? That they are merely drugged?’

Her lips curved; they were still plump and red, he saw, younger than her face would suggest.

‘What good would a dead person be to anyone?’

‘But plainly the widespread belief is that zombies are dead.’

‘Aye, of course. The zombies think they’re dead, and so does everyone else. It’s not true, but it’s effective. Scares folk rigid. As for “merely drugged”, though . . .’ She shook her head. ‘They don’t come back from it, ye ken. The poison damages their brains, and their nervous systems. They can follow simple instructions, but they’ve no real capacity for thought anymore – and they mostly move stiff and slow.’

‘Do they?’ he murmured. The creature – well, the man, he was now sure of that – who had attacked him had not been stiff and slow, by any means. Ergo . . .

‘I’m told, madam, that most of your slaves are Ashanti. Would any of them know more about this process?’

‘No,’ she said abruptly, sitting up a little. ‘I learnt what I ken from a houngan – that would be a sort of . . . practitioner, I suppose ye’d say. He wasna one of my slaves, though.’

‘A practitioner of what, exactly?’

Her tongue passed slowly over the tips of her sharp teeth, yellowed, but still sound.

‘Of magic,’ she said, and laughed softly, as though to herself. ‘Aye, magic. African magic. Slave magic.’

‘You believe in magic?’ He asked it as much from curiosity as anything else.

‘Don’t you?’ Her brows rose, but he shook his head.

‘I do not. And in fact, from what you have just told me yourself, the process of creating – if that’s the word – a zombie is not in fact magic, but merely the administration of poison over a period of time, added to the power of suggestion.’ Another thought struck him. ‘Can a person recover from such poisoning? You say it does not kill them.’

She shook her head.

‘The poison doesn’t, no. But they always die. They starve, for one thing. They lose all notion of will, and canna do anything save what the houngan tells them to do. Gradually, they waste away to nothing, and—’ Her fingers snapped silently.

‘Even were they to survive,’ she went on practically, ‘the people would kill them. Once a person’s been made a zombie, there’s nay way back.’

Throughout the conversation, Grey had been becoming aware that Mrs Abernathy spoke from what seemed a much closer acquaintance with the notion than one might acquire from an idle interest in natural philosophy. He wanted to get away from her, but obliged himself to sit still and ask one more question.

‘Do you know of any particular significance attributed to snakes, madam? In African magic, I mean.’

She blinked, somewhat taken aback by that.

‘Snakes,’ she repeated slowly. ‘Aye. Well . . . snakes ha’ wisdom, they say. And some o’ the loas are snakes.’

‘Loas?’

She rubbed absently at her forehead, and he saw, with a small prickle of revulsion, the faint stippling of a rash. He’d seen that before; the sign of advanced syphilitic infection.

‘I suppose ye’d call them spirits,’ she said, and eyed him appraisingly. ‘D’ye see snakes in your dreams, colonel?’

‘Do I— no. I don’t.’ He didn’t, but the suggestion was unspeakably disturbing. She smiled.

‘A loa rides a person, aye? Speaks through them. And I see a great huge snake, lyin’ on your shoulders, colonel.’ She heaved herself abruptly to her feet.

‘I’d be careful what ye eat, Colonel Grey.’

They returned to Spanish Town two days later. The ride back gave Grey time for thought, from which he drew certain conclusions. Among these conclusions was the conviction that maroons had not, in fact, attacked Rose Hall. He had spoken to Mrs Abernathy’s overseer, who seemed reluctant and shifty, very vague on the details of the presumed attack. And later . . .

After his conversations with the overseer and several slaves, he had gone back to the house to take formal leave of Mrs Abernathy. No one had answered his knock, and he had walked round the house in search of a servant. What he had found instead was a path leading downward from the house, with a glimpse of water at the bottom.

Out of curiosity, he had followed this path, and found the infamous spring in which Mrs Abernathy had presumably sought refuge from the murdering intruders. Mrs Abernathy was in the spring, naked, swimming with slow composure from one side to the other, white-streaked fair hair streaming out behind her.

The water was crystalline; he could see the fleshy pumping of her buttocks, moving like a bellows that propelled her movements – and glimpse the purplish hollow of her sex, exposed by the flexion. There were no banks of concealing reeds or other vegetation; no one could have failed to see the woman if she’d been in the spring – and plainly, the temperature of the water was no dissuasion to her.

So she’d lied about the maroons. He had a cold certainty that Mrs Abernathy had murdered her husband, or arranged it – but there was little he was equipped to do with that conclusion. Arrest her? There were no witnesses – or none who could legally testify against her, even if they wanted to. And he rather thought that none of her slaves would want to; those he had spoken with had displayed extreme reticence with regard to their mistress. Whether that was the result of loyalty or fear, the effect would be the same.

What the conclusion did mean to him was that the maroons were in fact likely not guilty of murder, and that was important. So far, all reports of mischief involved only property damage – and that, only to fields and equipment. No houses had been burnt, and while several plantation owners had claimed that their slaves had been taken, there was no proof of this; the slaves in question might simply have taken advantage of the chaos of an attack to run.