They surveyed earthworks dug into the ground. Teams of troopers in skinsuits were working in the trenches. They weren’t digging so much as refurbishing, Pirius saw. He had never seen earthworks so regular and neat—their walls were precisely vertical, their edges geometrically straight and dead neat. And he couldn’t see a trace of stray dust anywhere. The troops smiled as they worked, in precise formation.

In one part of the works the troops suddenly lunged out of their trenches and flopped onto the surface, across which they began to wriggle.

“They’re maneuvering,” said Pirius. “But it’s not an exercise. It’s more like a game.”

“Yes,” said Nilis. “And these earthworks are an ornamental garden. These folk have been isolated too long, Pirius. A trench is a place to fight and die. They have domesticated these trenches.”

Pirius slowly pieced together an understanding of this place.

Rocks were an essential element in most attacks on Xeelee concentrations; they provided cover, resources, and soaked up enemy firepower. But while most Rocks were purposefully deflected onto their required trajectories, Orion Rock, and a number of others, had natural orbits that took them into useful positions in the Core without deflection. So they could be used as cover, to mount covert operations.

But as the Core’s geography spanned light-years, travel times were painfully slow. The planners behind this place had been forced to think ahead, across no less than a thousand years—for that was how long Orion Rock would have to travel before it was in a position to be useful.

Nilis said gravely, “This is the scale of this war, Pirius. Orion Rock is like a generation starship sent to war: forty, perhaps fifty generations doomed to these dark tunnels, all the possibilities of their lives sacrificed to one goal, a strike on the Xeelee, a single assault that might be carried out in their children’s time, or their children’s children.

“A thousand years, though. On pre-Occupation Earth, a thousand years was a long time: time enough for empires to rise and fall, time enough for history. To us it is just a checkmark on a war planner’s chart!”

As the troops dug and marched and played at maneuvers, their mouths moved in unison, Pirius saw. They were singing again. But, thanks to some fault in the systems, he couldn’t hear their song.

They had been assigned a hangar, a huge one, beneath that paved-over crater where they had landed. Pirius went to inspect it. The hangar was big enough for a hundred greenships, let alone fifteen, and it was fully equipped with repair and maintenance facilities. Crisscrossed by walkways, full of hovering bots, the hangar was fully pressurized, although sections could be opened to vacuum when necessary. The working areas had been kept at microgravity—greenships were built for lightness, and were too frail to support their own weight under full gravity—but the floor and walkways were laced with inertial adjustors. Brightly lit by hovering globe lamps, it was a stunning facility by any standards.