The Seventh Empire is dying. After millenia of human expansion throughout the galaxy, the fabric of hyperspace is in tatters. Once routine, interstellar travel has become perilous. The Imperial fleets stay close to their home systems, whole sectors have become isolated from the galactic community, and for many, especially those on marginal worlds greatly dependent on interstellar commerce for their very survival, the only hope is Septimus.
Septimus is a marvel, a Dyson sphere on the very edge of the galaxy, an alien artifact that defies so many fundamental laws of physics, many in the Core Worlds still refuse to believe it to be anything more than a myth. For those who know the truth, however, Septimus is a beacon. So large is the sphere, the entire population of the galaxy could live comfortably inside. Unfortunately for the millions of galactic citizens who have made the dangerous voyage to Septimus, they find themselves trapped inside a cage with a monster. That monster is the Sindavar Extent.