Leto waited until she was kneeling atop him. It was not the same as the old times, he knew. She had no maker hooks and could not stand on his back. He lifted his front segments slightly off the surface.

“Why am I doing this?” she asked. Her tone said she felt silly up there.

“I want you to taste the way our people once moved proudly across this land, high atop the back of a giant sandworm.”

He began to glide along the dune just below the crest. Siona had seen holos. She knew this experience intellectually, but the pulse of reality had a different beat and he knew she would resonate to it.

Ahhh, Siona, he thought, you do not even begin to suspect how I will test you.

Leto steeled himself then. I must have no pity. If she dies, she dies. If any of them dies, that is a required event, no more. And he had to remind himself that this applied even to Hwi Noree. It was just that all of them could not die.

He sensed it when Siona began to enjoy the sensation of riding on his back. He felt a faint shift in her weight as she eased back on to her legs to lift her head.

He drove outward then along a curving barracan, joining Siona in enjoyment of the old sensations. Leto could just glimpse the remnant hills at the horizon ahead of him. They were like a seed from the past waiting there, a reminder of the self-sustaining and expanding force which operated in a desert. He could forget for a moment that on this planet where only a small fraction of the surface remained desert, the Sareer’s dynamism existed in a precarious environment.

The illusion of the past was here, though. He felt it as he moved. Fantasy, of course, he told himself, a vanishing fantasy as long as his enforced tranquillity continued. Even the sweeping barracan which he traversed now was not as great as the ones of the past. None of the dunes were that great.

This whole maintained desert struck him suddenly as ridiculous. He almost stopped on a pebbled surface between the dunes, continuing but more slowly as he tried to conjure up the necessities which kept the whole system working. He imagined the planet’s rotation setting up great air currents which shifted cold and heated air to new regions in enormous volume—everything monitored and ruled by those tiny satellites with their Ixian instruments and heat-focusing dishes. If the high monitors saw anything, they saw the Sareer partly as a “relief desert” with both physical and cold-air walls girdling it. This tended to create ice at the edges and required even more climatic adjustments.

It was not easy and Leto forgave the occasional mistakes for that reason.

As he moved once more out on to dunes, he lost that sense of delicate balance, put aside memories of the pebbly wastelands outside the central sands, and gave himself up to enjoyment of his “petrified ocean” with its frozen and apparently immovable waves. He turned southward, parallel to the remnant hills.