Deep inside the Cavity, a long way inside the Front, Orion Rock was buried in the North Arm of the Baby Spiral.

To reach it, Exultant Squadron formed a tight convoy. The ten prime greenships, with five backups, were at the center. All the greenships had been modified with the gear for Project Prime Radiant, but the equipment was bedded in now, and after the hours of training flights the crew knew how to handle their ungainly craft. The fighting ships were accompanied by equipment freighters, tenders, and other support craft, and a handful of command vessels, including Commissary Nilis’s corvette. One massive Spline warship loomed over them. Bristling with weapons, its moonlike bulk dwarfed its charges.

It was an unlikely flotilla, Pirius supposed. It was strange to reflect that on this handful of battered, hastily modified old hulks might rest the destiny of the Galaxy.

The group sailed through the Front and made their way down the spine of the Baby Spiral’s arm, moving in a series of FTL hops and sublight-drive glides. Despite the time pressure, the only way to proceed was cautiously: the spiral arm was a crowded corridor of molecular dust, drifting rock, and young stars, a difficult jaunt. But there was so much noise and clutter here in this tunnel of bombarded gas that there was a good chance they would remain undetected by Xeelee scouts all the way in.

After two sleepless days and nights, with the crews stressed-out and weary, they reached Orion Rock.

Pirius, sitting in his pilot’s blister, gaped. He had never seen anything like it. The Rock shone.

Like every asteroid of its size, it was an aggregate shape as lumpy as a clenched fist, deeply pocked by impact craters. But on this Rock the surface had been worked, every square centimeter of it. Every crater hosted a landing pad or a dry dock or a portal, and away from the craters the land had a peculiar ridged texture. As they approached, Pirius saw it was covered by a dense scribble of trenches and foxholes, zigzagging at precise ninety-degree corners. It was ornate, even decorative, like a maze. You could tell that people had been here for a long time.

Orion had been spawned out of random accretions in this spiral arm long ago, and had since drifted down its center line. As it had required no human intervention to steer it onto a path that directed it straight at the Xeelee concentrations, the Rock was a marvelous natural blind. It had been occupied by humans for a thousand years, and the results of that occupation were visible on its surface—and yet it was still unsuspected as a military asset by mankind’s foe.

The greenships and their escorts settled on a landing pad at the center of the largest crater—all save the big Spline, which took up a watchful position directly overhead, like a fleshy eye.