He can't remember how he got here, or how long he's been here. He is standing on a foggy plain - there is nowhere in Thule this flat - the ground is bare and barren, stretches of rock mingling with stretches of rock-hard packed dirt, all mostly obscured by a pale grey mist that clings to the ground and swirls around his ankles. A much fainter mist veils the horizon, blending land and sky into a seamless white dome.

There's only one landmark visible, a round shape looming in the middle distance. He walks toward it.

Broad round steps encircle the base of a bizarre sculpture. There's a huge blocky ring made up of three concentric rings divided equally into seven parts each, and on each ring the seven parts are coloured in the seven colours of the rainbow, red orange yellow green blue indigo violet. The rings are turning independently at three slightly different speeds. Two thick brackets rise from the steps, angled in toward the center of the circle, to hold the base of the ring; but it seems impossible that they could actually be held up that way, not and keep turning like that.

It looks like the outer edge of the outermost ring is about level with the ground, hidden inside the round not-quite-pyramid of steps; the inner edge of the innermost ring is level with the topmost step, which looks to be about six feet off the ground. The space inside the ring is something like twelve feet wide, edge to edge.

Every part of every ring has a panel with three symbols on it. The middle one on each is unique: the outermost ring is all flowers whose outlines he doesn't recognize, and the middle ring birds likewise, and the inner ring all cut gemstones which are fundamentally unrecognizable in outline because that's not how gemstones work. Then there's a symbol on the left side of the panel, and there seem to be seven of those, and a symbol on the right side, of which there seem to be three: white circle, grey circle, black circle, each drawn and decorated slightly differently.

As he watches, the green section on the middle ring - is that a hummingbird? - clicks into place in exactly the topmost position. The ring stops. The panel glows green. Faint threads of green smoke curl inward from its surface, reaching into the space inside the ring.

The outer ring stops next, on blue. It lights up and adds threads of blue smoke to the mix. Then the inner, on orange, and the smoke weaves together so thick in its twining colours that he can't see through the middle of the ring at all, in green and blue and orange and for some reason white - there are two white circles among the three lit-up panels, maybe that's why -

Curious, he walks up the steps and attempts to give the inner ring a shove. It turns surprisingly easily; the orange panel with its white circle goes dim, its smoke clears from the structure's interior, and then the red panel clicks into place with its grey circle and the space is filled with blue, green, red, and grey.

He keeps turning the ring. Violet panel, grey circle. Indigo panel, white circle. Blue panel, black circle - and now there's no extra smoke, just blue and blue and green.

It occurs to him vaguely that this scenario is completely insane and he's probably dreaming or something. He shrugs and keeps fiddling with the rings. Turning the middle one is harder than the other two; he gives up and leaves it on the hummingbird.

Having two black circles puts black smoke in the middle of the ring, just like with white and grey. Three grey circles produces a lot of grey smoke. He can't check three white or three black without turning the middle ring, but he figures it's probably the same.

Two of the same colour, like blue and blue or red and red - or green and green - adds depth and shade to the relevant colour of smoke inside the ring. Two of the same left-hand symbol does something harder to define but equally interesting to the way the smoke moves. The three green panels all have the same left-hand symbol, which no other colour does; when he turns the rings to green-green-green, the result is kind of magnificent: intricate spirals twisting in toward the center and then circling out again, in every shade of green imaginable. He sticks his hand into it to mess up the pattern. The smoke tangles up around the disturbance and then disentangles itself when he takes his hand away. It's fun, so he does it again, waving his arms through the patterns.

What happens if he jumps right through the middle? Well, he'll probably land badly on the steps on the other side of the ring and break something, but this is a dream so he doesn't care. He runs up the steps and leaps through -

He sees the disturbance he made in the smoke, just as impressive as he thought it would be, an enormous green splash trailing after him through the air. But he never hits the ground. He's falling sideways through thick grey fog, blurring until he can't see anything, until he himself disappears -

He opens his eyes.