Leaning over, Yagharek could feel heat gusting from the lamplit depths within. The night outside was warm, but the temperature within must be very high.

He wound the grappling hook carefully around the metal joist at one side of the crack and tugged it hard to ensure it was secure. Then he wrapped the end of the rope three times around his waist. He gripped it near the hook, lay across the girder and put his head in through the lips of broken glass.

It felt like pushing his face into a bowl of strong tea. The air inside the Glasshouse was hot, almost stiflingly so, and full of smoke and steam. It shone with a hard, white light.

Yagharek blinked his eyes clean and shielded them, then looked down on the cactus town.

In the centre, below the massive nugget of glass at the dome’s tip, the houses had been cleared away and a stone temple had been built. It was red stone, a steep ziggurat, that reached a third of the way to the Glasshouse roof. Every stepped level was lush with desert and veldt vegetation, abloom in garish reds and oranges against their waxy green skins.

A little rim of land, about twenty feet wide, had been cleared all around it, beyond which point the streets of Riverskin had been left. The cartography was a snarled puzzle, a collection of road-ends and the rumps of avenues, here the corner of a park and there half a church, even the stump of a canal, now a trough of stagnant water, cut off by the edge of the dome. Lanes criss-crossed the little township at odd angles, segments cut from longer streets where the dome had been placed over them. A little random patch of alleys and roads had been contained, sealed under glass. Its content had changed even as the outlines remained mostly the same.

The chaotic aggregate of street-stubs had been reformed by the cactacae. What, years ago, had been a wide thoroughfare had been made a vegetable garden, the edges of its lawns flush with the houses on either side, little trails from front doors indicating the routes between patches of pumpkin and radishes.

Ceilings had been removed four generations ago to convert human houses into homes for their new, much taller inhabitants. Rooms had been added to the tops and backsides of buildings, styled like weird miniature effigies of the stepped pyramid in the centre of the Glasshouse. The additional buildings had been wedged into every space possible, to cram the dome with cactacae, and strange agglomerations of human architecture and monolithic, stone-slab edifices stretched in big blocks of variegated colour. Some were several storeys tall.