To paraphrase author Terry Pratchett, though light might think it travels fastest, darkness

appears always to find a way of arriving first. Wherever light goes it seems, the darkness

is already there, ready in waiting. In the United States's Detroit Institute of Arts

hangs a strange and captivating painting of an unconscious woman dressed in white. Her

body stretched out across a bed with her arms and head dangling toward the floor. Squatting

on her chest, staring out at the picture with dark red eyes, is a peculiar and somewhat

grotesque, cherubic imp. Though the woman is bathed in light, the imp, clearly a creature

of the night, resolutely remains, steadfastly refusing to be cast back into the shadows.

And in the darkness beyond, another creature is emerging, a black horse with flaired nostrils

and bright white eyes. The Nightmare, painted by Henry Fusoli in 1781, serves as an ironic

repost to the Enlightenment, Europe's pervading cultural movement of the day. Or as art historian

Dr. Noel Paulson puts it, the painting demonstrates the ultimate futility of light to penetrate

or explore the darker realms of the unconscious. For many, myself included, the picture brings

to mind the terrifying and vivid effects of sleep paralysis, an uncanny phenomenon that

can result in the seemingly very real experience of believing you have woken from sleep, only

to find yourself completely paralyzed. Though I am now familiar with the experience enough

to know it when it happens, what I have never grown used to are the occasions when I believe

I have woken up to find not only am I unable to move, but that there is a shadowy, humanoid

creature standing over me. Much worse, when that figure scurries out from the corner of

the room and launches itself at me as I fight to regain consciousness. It was some time

before I discovered others had also had similar experiences to myself, and that these illusory

creatures had a name, shadow people. The term's modern iteration was popularised by Art

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