Outside the dome, the air darkened inexorably. With the onset of the night, the bright rays that burst from the glass globe in the dome’s roof were snuffed out. The Glasshouse grew suddenly dimmer and more cool. But much of the heat was retained. The dome was still far warmer than the city outside. The lights from the torches and the buildings within reflected back on the glass. To the travellers looking back on the city from Flag Hill, to the slum-dwellers gazing desultorily down from the towerblocks of Ketch Heath, to the officer glancing from the skyrail and the driver of the south-bound Sud Line train, peering through smokestacks and flues, over the smoke-soiled roofscape of the city, the Glasshouse looked stretched out taut, distended with light.

As dusk fell, the Glasshouse began to glow.

Clinging to the metal on the inside skin of the dome, unnoticed like some infinitesimal tic, Yagharek slowly flexed his arms. He was affixed to a little knot of scaffolding about one-third of the way down the height of the dome. He was still easily high enough to look down on all the housetops, the tangles of architecture on all sides.

His mind was poised in yajhu-saak. He breathed slowly and regularly. He continued his hunter’s search, his eyes flitting restlessly from point to point below him, not spending more than a moment on each place, building up a composite picture. Occasionally he would unfocus and take in the whole sweep of the roofs below him, alert for any strange movements. He returned his attention often to the scum-covered trench of water where he had told Shadrach to assemble the others.

There was no sign of the band of intruders.

As the night deepened, the streets cleared at extraordinary speed. The cactacae flocked back to their houses. From a teeming township, the Glasshouse emptied, became a ghost town in a little over half an hour. The only figures left on the streets were the armed patrols. They moved nervously through the streets. Lights from windows were dimmed as shutters and curtains were closed. There were no gaslights in these streets. Instead, Yagharek watched lamp-lighters walk the length of the streets, reaching out with flaming poles to ignite oil-soaked torches ten feet above the pavements.

Each of the lamp-lighters was accompanied by a cactacae patrol, moving nervously, pugnacious and furtive through the obscuring streets.

On the top of the central temple, a group of cactus elders was moving around the central mechanism, pulling levers and tugging at handles. The enormous lens at the top of the device swung down on a ponderous hinge. Yagharek peered closely, but he could not discern what they were doing or what the machine was for. He watched without comprehension as the cactacae swung the thing around, about a vertical and a horizontal axis, checking and adjusting gauges according to obscure calibrations.