What really mattered to Alia nowadays was Skimming.

She met her sister in the Engine Room, the deepest bowel of the Nord, in steel-gray light, where hulking, anonymous machinery loomed. The sisters faced each other and laughed at the delicious prospect of what was to come.

Like Alia, Drea was naked, the best way to Skim. Drea’s body, coated with golden hair, was neatly proportioned, with her arms only a little shorter than her legs, and she had long toes, not as long as her fingers but capable of grasping and manipulation. It was a body built for zero gravity, of course, and for hard vacuum, the natural environment of mankind, but it was believed that this body plan was pretty much the same as that of the original human stock of old Earth.

Drea was ten years older than Alia. The sisters were very alike, but there was more gravity to Drea, a little more levity to Alia. As the light shifted, multiple lids slid across Drea’s eyes.

Drea leaned close, and Alia could smell the sweetness of her breath. “Ready?”

“Ready.”

Drea grasped Alia’s hands. “Three, two, one—”

Suddenly they were in the Nord’s Farm deck.

This was a high, misty hall, where immense ducts and pipes snaked down through the ceiling, lamps shed a cool blue-white glow, and green plants burgeoned in clear-walled hydroponic tanks. The Nord was a starship, a closed ecology. The big pipes delivered sewage and stale air from the human levels above, and carried back food, air, and clean water.

Alia breathed deep. After the cold, static austerity of the Engine Room she was suddenly immersed in the Farm’s vibrant warmth, and the deck plates thrummed in response to the huge volumes of liquid and air being pumped to and fro. Even the quality of the gravity felt subtly different here. Alia had felt nothing of the Skimming: no time passed during a Skim, so there was no time for sensation. But the transition itself was delicious, a rush of newness, like plunging from cold air into a hot pool.