For centuries, the galaxy flourished under the benevolent aegis of the Empire. Yet however great the Empire grew as it spread across the stars, it knew that others had gone that way before: it depended upon a network of interstellar gates, wrought from the fabric of reality with powers beyond any but their vanished Builders.

In time, these Builders came to be revered by some as gods. And as so often before, disputes about their will led to war.

The Guardian sect sought to end use of the Gates. With the forces of interstellar civilization arrayed against them, their cause seemed hopeless. But then the Guardians came to possess bulk antimatter, and they began to use it to collapse the wormholes within Gates, preventing, they supposed, the profanation of heaven. Dozens of systems were cut off from Connected Space with each attack. Galactic commerce and government were shattered.

At last, war even came to the frontiers of the Empire. A long dark age brought ruin to countless inhabited planets. Ten worlds, their only known link with inhabited space cut by an antimatter attack, allied to rebuild starfairing civilization within their handful of still-linked star systems. Their inhabitants do not know what has transpired outside. Have the Antimatter Wars ended? Were the Guardians defeated, or is the territory of the Alliance all that remains of Connected Space? Perhaps afraid of the answers they might find, they made little attempt to find out.

After many years of uncertainty, an unknown space probe emerged from a wormhole on the Allied frontier, provoking political changes favourable to an investigation. The Assembly has decided to send a grand mission of exploration to survey space through this wormhole, which leads away from what was once the pale of Imperial colonization. The future of the Alliance, and possibly of all that remains of interstellar civilization, hinges on what is to be found beyond the Ten Worlds...