The exhilarating flight was always brought to an abrupt halt in the same place – a vast dust-scoured desert littered with razor-sharp rocks and shards of broken crystal, stretching out seemingly forever beneath a sky the colour of vomit. Every breath that Dorothy tried to take in this barren place seemed to sear the inside of her lungs, and with every step she took, the edges of the rocks threatened to slice though the soles of her shoes.

All around her she could see other figures making their painful way across the hostile sand, too far away to make out their faces, but close enough to hear their anguished cries. There were scores of them; men, women, children, all making their way towards a huge building on the horizon.

The structure was vast, its cracked and crumbling walls seemingly made out of rough, dark pumice. Huge chimneys rose from its centre, belching thick, oily smoke into the sick-looking sky and the sound of grinding engines reverberated from within. Fingers of lightning constantly tore from the clouds that roiled above it, and cracks of thunder echoed across the barren landscape.

It was a vision of hell itself.

Dorothy tried to force her subconscious to remember something useful, some face that she recognised, or a detail about the building that seemed familiar, but any memory that might help unravel the cause of her nightmare was always drowned out by the appearance of … the creature.

The event that tore her from her sleep each night was never exactly the same, but it always started the same way. The boiling clouds started to thicken and swell, the pale yellow of the sky darkening to a deep pus-like orange. Deep in the clouds a huge dark shape started to solidify.

All around people started to flee, and Dorothy fled with them, not knowing what it was she was running from, but knowing instinctively that it was the right thing to do. The razor edges of the rocks tore at her feet making her cry out in pain with every footfall. She dared not think what damage they would do to her hands and face if she lost her balance and fell.

From behind her there was a sudden crack of thunder, immediately followed by the sound of hoarse, animal breathing as something unseen bore down on her.

And every night Dorothy turned to face whatever the horror might be, only to find a fast, scabrous talon, its fingernails cracked and dirty, reaching out for her, engulfing her, snatching her off her feet and lifting her towards a face so terrible, so monstrous that she woke literally believing that she was fighting for her life.