He stopped at a work station and fingered through drawers of small tools and pesticide patches, gloves and bags. He selected three tiny patches and put them in a plastic bag, then slipped the bag gently into the walker’s pocket. The patches were clever pesticides, biosaboteurs designed to provide plants with systemic defenses; he had been reading about them, and knew of a combination that in animals would be deadly to the organism. .

He put a pair of shears in the walker’s other pocket. Narrow gravel paths led him up between long beds of barley and wheat, back toward the city proper. He went in the lock leading into town, unclipped his helmet, stripped off the walker and boots, transferred the contents of the walker pockets to his coat. Then he went back into the lower end of town.

Here the Arabs had built a medina, insisting that such a neighborhood was crucial to a city’s health; the boulevards narrowed, and between them lay warrens of twisted alleyways taken from the maps of Tunis or Algiers, or generated randomly. Nowhere could you see from one boulevard to the next, and the sky overhead was visible only in plum strips, between buildings that leaned together.

Most of the alleys were empty now, as the party was uptown. A pair of cats skulked between buildings, investigating their new home. Frank took the shears from his pocket and scratched into a few plastic windows, in Arabic lettering, Jew, Jew, Jew, Jew, Jew. He walked on, whistling through his teeth. Corner cafés were little caves of light. Bottles clinked like prospectors’ hammers. An Arab sat on a squat black speaker, playing an electric guitar.

He found the central boulevard, walked up it. Boys in the branches of the lindens and sycamores shouted songs to each other in Schwyzerdüütsch. One ditty was in English: “John Boone/Went to the moon/No fast cars/He went to Mars!” Small disorganized music bands barged through the thickening crowd. Some moustached men dressed as American cheerleaders flounced expertly through a complicated can-can routine. Kids banged little plastic drums. It was loud; the tenting absorbed sound, so there weren’t the echoes one heard under crater domes, but it was loud nevertheless.