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 secular 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 in desperation they began to use it to collapse the wormholes within Gates. Dozens of systems were cut off from Connected Space with each attack. Galactic commerce and government were shattered.

War even came to the frontiers of the Empire. Dark centuries of collapse passed. Ten worlds, their only known link with inhabited space cut by an antimatter attack, have Allied to rebuild starfairing civilization within a 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, little attempt was made to investigate by the Allied Worlds.

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 the pale of Imperial colonization. It is agreed that 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...