Rig Gaines, suddenly uncomfortable with events, not to say his place in them, rode the Uptown Six down to Alyssia Fignall’s archeological project, hoping he might persuade her to leave the planet with him before things took their inevitable turn for the worse. He didn’t imagine she would.

The weather was hot, her house empty. In the cloister he found a note she had left: ‘Rig, when the rains come, something beautiful happens here.’ It didn’t look like rain. The stones were hot to the touch. Rather than arriving with the sunlight, heat seemed to generate itself between the eight rhyolite pillars around the fountain and spray upwards from there. Gaines sat all afternoon waiting for Alyssia, watching the glare move across the smooth oval cobbles. At four o’ clock, the sky clouded over. After a few grand but silent flashes of lightning, it seemed nothing else would happen. But by five it was pouring with rain.

‘Jesus, Alyssia,’ Gaines said. He went out to look for her, and was promptly drenched.

The town square he found empty but for some children, who ran about in front of him laughing and calling ‘La Cava! La Cava!’ in excited voices. He followed them into the covered market. That was deserted too. All over the Halo, people sell each other ordinary things, from empty bottles to leather belts. Here the stalls offered drip trays and shoes, ten inch holograms of very fat children wearing lace. Then loaves of bread like large smooth stones on a beach. Then meat. Strips, strings and slivers of meat. Long thin slices of meat hung up like translucent shower-curtains, with a sour iron smell. ‘Hey kids,’ called Gaines, temporarily unable to locate them. ‘La Cava!’ they called. The market was a dark, confusing maze. A workman’s café offered sesos rebosadas, sautéed brains, eaten standing up. His nostrils were full of that idea until the children led him into the light on the other side, and a different smell took over. Rain poured from the market eaves. The kids beckoned. Gaines stood looking out but suddenly found it impossible either to move or to describe what was happening in the second, smaller square which now revealed itself.