[Not sure what category this falls under. Put it this way, there'll be blood.]
This was a peaceful part of the sea, far from the swimmers and their noise. Out here the land was a distant memory, nothing but the curve of the world on the horizon, unless you got high enough to see the edge of Lambastia in the distance. The surface of the sea was undisturbed apart from the ruffling of the water by the wind.
An enormous black cube floated several meters above, the setting sun reflecting off its smooth surface. There was no sign of any door or window; it was entirely featureless and still in the air. Occasionally a bird would fly past it, sometimes with a squawk of alarm. Once something briefly leapt out of the water and splashed its surface; it dried almost instantly.
Inside sat Heulwen Pugh.
She perched on the bed that took up a large part of the floor, and watched the rippling water through the window that was most of the front wall. Or possibly the back wall, or the side, but such distinctions were unimportant. It all looked the same from the other side of the glass, anyway.