As the car emerged from among the downtown buildings expanses of blue sky became visible and Hasson saw above him a fantastic complex of aerial highways. The bilaser images looked real but not real — curves, ramps, straights, trumpet-shaped entrances and exits, all apparently carved from coloured gelatine and bannered across the sky to guide and control the flux of individual fliers whose business brought them into the city. Thousands of dark specks moved along the insubstantial ducts, like the representation of a gas flow in a physics text.

“Pretty, isn’t it? Some system!” Werry leaned forward, peering upwards with enthusiasm.

“Very nice.” Hasson tried to find a comfortable posture in the car’s too pliant upholstery as he studied the three-dimensional pastel-coloured projections. Similar traffic control techniques had been tried in Britain back in the days when there still had been hope of reserving some territory for conventional aircraft, but they had been abandoned as too costly and too complicated. With million of individuals airborne above a small island, many of them highly resistant to discipline, it had been found most expedient to go for a simple arrangement of columnar route markers with bands of colour at different altitudes. The most basic bilaser installations could cope with the task of projecting the solid-seeming columns, and they had a further advantage in that they left the aerial environment looking comparatively uncluttered. To Hasson’s eyes, the confection hovering above Edmonton resembled the entrails of some vast semi- transparent mollusc.

“You feeling all right, Rob?” Werry said. “Is there anything I can do for you?”

Hasson shook his head. “I’ve been travelling too long, that’s…”

“They told me you got yourself all smashed up.”

“Just a broken skeleton,” Hasson said, modifying an old joke. “How much did they tell you, anyway?”