‘Sounds like good advice to me, Tom,’ Alice said with a smile.

I smiled back, but then the expression on her face changed to one of fear and horror. She was staring at the door, as if sensing danger.

Suddenly it burst open and half a dozen large men brandishing clubs surged in. They wore leather jerkins with the three-legged insignia – yeomen. A tall man with a dark moustache and carrying a sword at his hip – clearly their leader – followed them inside. They all halted near the door, their eyes sweeping the room, looking at the occupants of each table as well as those standing at the bar. It was then that I noticed they had a prisoner.

He also wore a leather jerkin with the badge. It accentuated his bulk; he was tall and very thick-set. Why would they hold one of their own captive? I wondered. What had he done wrong? Then I saw that the man was bound, but in a strange, cruel way. A length of fine silver chain ran from each ear to the hands of the two guards who flanked him. His ears had been pierced very close to his head and the holes through which the chains passed were red and inflamed.

The prisoner sniffed loudly three times and spoke, his voice as harsh as a file rasping against metal. ‘I smell woman! There’s a woman here, Commander Stanton,’ he said, turning towards the tall man with the moustache.

The guards all stared at Alice. She was the only female in the room.

The prisoner started to approach our table, the two flanking guards keeping pace, with Stanton further to one side. As he did so, I noticed two things simultaneously: the first was that he was blind, his eyeballs milky-white; the second sent a tremor of fear down my spine and I felt the hairs on the back of my neck rise.

He had dark, curly, matted hair – more like the hide of an animal than human hair. Through it, very high on his forehead, protruded two very short curved horns. They were white, and each came to a sharp point. This wasn’t a man; it was an abhuman, the result of a union between the Fiend and a witch.

‘This is no woman!’ laughed Stanton. ‘It’s just a scrawny girl with dirty feet. Try again!’

This time the abhuman didn’t sniff; he just peered at Alice as though his blind eyes could actually see her. A puzzled expression creased his face.

‘Well, come on,’ the commander demanded in an impatient voice. ‘Is the girl a witch or not?’

‘She has darkness inside her!’ cried the abhuman. ‘Dark power!’

‘Well, that’s all we need to know! Seize her, lads!’ he cried, and two men stepped forward and dragged Alice off her stool. She didn’t try to struggle – her eyes were wide and filled with fear.

I knew just one thing – wherever they took Alice, I had to go too. If she was separated from the blood jar, the Fiend would take his revenge on her. However, as it turned out, I didn’t need to do anything.

‘Check the other two!’ Stanton commanded. ‘They were talking to a witch. Could be they’re in league together. Maybe one of them’s a warlock…’

The abhuman looked at Captain Baines next. ‘No darkness here,’ he growled.

‘What about the boy, then?’

Now it was my turn, but after studying me with his blind eyes, the creature looked even more puzzled. His mouth opened twice to reveal two rows of sharp yellow teeth, but no words came out.

‘We haven’t got all day. What’s the problem?’

‘A sliver of darkness is buried deep within his soul. A very small piece…’

‘It’s enough! Bring him along!’ snapped Stanton. ‘It’s a long time since we tested a male witch. They’re very rare.’

I just had time to glance back at Captain Baines’s anxious face before I was seized too, and moments later my hands were tied behind my back and I was outside the tavern with Alice, being dragged by rough hands up the hill towards the main thoroughfare.

After a forced march through the busy streets, during which we were jostled, jeered and spat on, we arrived at last at the outskirts of the town and were pushed aboard a dray-cart pulled by four sturdy shire horses. The driver cracked his whip and we set off along a track; having glanced up at the stars and noted the position of the Plough constellation, I judged it was taking us roughly north-west. Alice and I weren’t alone in the cart. We were guarded by three thick-set men with clubs who looked more than willing to use them. Our hands were still tied and there wasn’t the slightest chance of escape.

The men didn’t speak at first and seemed content to stare at us. We both lowered our eyes, not wanting to give them any excuse for violence, and kept quiet, but after a little less than an hour, I judged, one of them nudged me with his club.

‘See that, boy?’ he said, pointing to his right.

In the distance, lit by the moon, was some sort of fortification. I could see a tower surrounded by castellated walls, with a mountain beyond it.

‘That’s Greeba Keep,’ he continued. ‘You might just live to see it again!’

The other yeomen laughed. ‘But once in there you’ll wish you’d died! It’s the lucky ones who are pulled out dead!’ said one.

I didn’t bother to ask him what he meant and remained silent until the cart finally came to a halt. We seemed to have reached a village. It was surrounded by trees, and hills rose up on either side. We were pulled down from the cart and taken past a large, curious mound of earth. It was shaped like a barrow but had four tiers. I’d never seen anything quite like it. Beyond stood another stone tower – this one much smaller than the first. I wondered if it was for holding prisoners, and was soon proved correct.

We were dragged up some steps to a door about halfway up the tower, and after our hands had been untied we were thrust inside. The door clanged behind us, a key turned in the lock and the guards went back down the stairs, their footsteps echoing off the stones.

I looked about me. A single candle stood in a recess in the wall, flickering in the draught from a narrow window far above. The cell was circular, with no furniture and only dirty straw covering the damp flags of the floor.

‘Don’t like this place much,’ said Alice, her voice hardly more than a whisper.

‘You may not like it, girl,’ said a voice from the shadows to our right, ‘but you’d better make the best of it. It’s the most comfortable you’ll ever be again. This is the Tynwald witch tower – after you leave here, there’s only pain and death to look forward to.’

Someone stepped out of the shadows to confront us. It was a tall girl of about eighteen or nineteen with dark glossy hair which reached down to her shoulders. She wore a pretty blue dress and her skin was clean and shining with health. She didn’t look much like a prisoner.

‘Came across the water from the County, did you?’ she asked.

I nodded. ‘My name’s Tom Ward and this is my friend, Alice.’

She glanced at Alice then gave me a warm smile. ‘My name’s Adriana Lonan,’ she said. ‘I was born and bred on Mona and they’ve left me alone until now. But everything’s gone crazy and they’re testing even their own folk to see if they’re witches.’

‘Are you a witch?’ I asked.

Adriana nodded. ‘I’m a bird witch,’ she said.

‘You mean you have a bird for a familiar,’ Alice corrected her.

The girl tossed her hair and frowned. ‘I don’t have a familiar. Don’t give my blood to anything. Not dark stuff like that. I’m a bird witch. Birds are my friends. We help each other. What about you, Alice? Are you a witch?’

Alice shook her head. ‘I come from a clan of Pendle witches and I was taught the dark craft for two years. But no, I’m not a witch. Ain’t right that we’ve been brought here, especially Tom. He’s a spook’s apprentice and fights for the light. They say he’s a warlock, but that ain’t true.’

Adriana stared at me, her face very serious. ‘Did Horn sniff you out?’

‘The abhuman? Yes,’ I told her. ‘He said Alice had darkness inside her and that I had a sliver of dark too.’