That would have been the time to turn back. There, under the cold blue sky with its pale, liquid sun and the playful fingers of the frosty air pinching at the areas of exposed skin.

I walked quietly, deciding, without really knowing it, that I would be best served by standing in the existing footsteps. I had a fear of putting my foot in one of the trenches made by the cow’s hooves and twisting my ankle – leaving myself immobile and vulnerable on the cold hard ground.

I smelled the building before I reached it. The reek was almost physical: a ghastly, chemical tang that seemed to reach into my mouth and nose like tree roots and which made tears instantly spring to my eyes. I stopped where I was, a dozen steps from the entrance; that rectangle of complete blackness set into the old, lichen-mottled stone.

There was a noise from within. It was a soft, damp sound, like a boot being pulled from thick mud. There was a rhythm to it. As I stood there I found myself able to count the beats between each occurrence. I stayed perfectly still. Heard it half a dozen times.

There was nothing inviting about the little stone structure. The stench, the sound, the sight of it, all spoke to me of something from the most menacing of fairy tales. And yet I needed to know. Despite everything, despite the risk, despite the damn stupidity of pressing on, I had to know what was inside.

Softly, barely lifting my feet from the ground, I crossed to the door of the building and peered inside.

It took a moment for my eyes to adjust. The smell that emanated from the darkness was almost unendurable. My eyes started streaming immediately and I felt a cough start to tickle at my chest and throat. It was through a blur that I saw the thing within. It was through a veil of tears and dread and against the surging of my own blood in my ears that I saw the figure in white standing, bent-backed, in that room of skulls.

My senses were flooded. It all came at me like a shotgun blast. The shelves, floor to ceiling, with their hideous array of perfect, moon-bright bone. Horns. Teeth. Eye sockets. Grinning smiles and jutting jaws, all denuded of flesh, feathers or fur. The soft, blood-red light of the gas-lamp, giving off only a whisper of illumination at the figure’s right hand.

He stood with his back to me, stirring the great wooden pot like a witch with a cauldron; the metrical thump of his large wooden mortar sploshing through the liquid to create the sound which had frozen me where I stood.

He was naked from the waist up. His skin was as white as the skulls that lined the wall and bore the scars of a life lived hard. His spine curved slightly, like a rat’s tail in repose.