Tub.

There was a bath tub. That was the main thing. The room was otherwise empty, with three large rectangular windows punctuating the far wall.

But the most important thing was the tub, which was filled with hot water. I stood over it, holding a sachet of brown powder in my hand. I tore the sachet open and sprinkled the powder into the water. The steam curled upwards like a crab claw.

Then - and I have no idea how this happened - I was in the tub. Some time had passed. I knew this because the water I was lying in was now cold. I also couldn't open my eyes. They seemed glued shut somehow. I had a thought that filled me with utter dread, and that thought was: 'Uh oh.'

The tub was full of eels. Thousands of black, baby eels. Had this happened before? The situation seemed familiar somehow. I couldn't see them, but they were there all right, entwined in my hair; clustered at my scalp, my groin, armpits, eyebrows, eyelashes. For now they were asleep, but I knew that any movement - even the opening of my eyelids - would wake them.

I began to lift my hand out of the water, in an achingly slow arc. There was a technique for getting oneself out of a situation like this - which I'd read about in a textbook or magazine - if I could only remember it. It involved math, as I seemed to recall. Something to do with angles.

I'd always hated trig.