Brooding over the immensity of the plain below was Canal City 4. Covering the entire city like a tremendous bubble was the iridescent dome of fused-quartz. The tiny fleet of ore-lighters nosed through the valves of airlock after airlock and headed across town toward the sprawling terraces of the freight docks. Like a chain of brightly silvered pumpkin seeds, the clumsy craft wound in and out among the towers of the 7th level, down to the freight docks.

Heydrick took his prisoner through the airlock in the freight terminal to condition her and himself for street-level atmosphere, then went out on the huge platform again.

Pausing only long enough to ask a robot attendant for information, Heydrick pushed the button to stop a descending elevator.

"Labor trouble—the workers are picketing—riots have broken out at street level," droned the mechanical voice of the robot.

A crowded car stopped, signalling raucously. Heydrick showed his badge to the robot pilot. "Street level," he said crisply. "Space Patrol priority." The robot grunted. "We have orders not to stop unless it's vitally necessary."

"It's necessary."

Jumbles of neo-plastic architecture, rising tier on tier above the series of terraces on which the city was built, whirled upward past the descending car.

On the street level, all was bustle and confusion. A polyglot crowd composed of every human and near human species in the universe jammed the streets. Stares followed the I.P.S. uniform as Heydrick pushed out of the elevator. A few people gave nods of respect, but in most faces burned a sullen hatred and resentment.

Ria followed him in stolid silence as the handcuffs tugged at her. The knots of angry people came suddenly in focus and she had a moment's desperate inspiration.