The Age of Death ended countless millennia ago. No longer burdened by limited lifespans, the immortal humans who populate inhabited space now have the luxury to travel vast distances disembodied, as streams of data.

For twenty thousand years, every observable phenomenon in the universe has been successfully explained by the Sarumpaet Rules: the laws governing the dynamics of the quantum graphs that underlie all the constituents of matter and the geometric structure of space-time. Scientist Cass has designed a set of graphs that comprise a different type of physics. She travels to the remote planet of Mimosa to test her findings. Unfortunately the results are a reversal of the expected outcome and the scientists create a rapidly expanding vacuum which begins to eat its way through the galaxy, destroying thousands of inhabited planets in its wake.

Six hundred years later, on a ship called the Rindler, which coasts along at the same speed as the vacuum’s border, Tchicaya joins a gathering of people from all the remaining worlds to study the vacuum. Tension arises between the Yielders - those who want to stop the vacuums progress but preserve it - and the Preservationists who want to destroy the vacuum. Amid the internal conflict, new evidence suggests that something previously unimaginable is rapidly growing deep within the mysterious, 600-light-years-wide vacuum.

Greg Egan is considered a master of science fiction. This novel is an example of his expertise at developing scientific theory into a novel, but the scientific jargon makes it difficult to follow at times. Though the plot is original, and the philosophical questions it raises intriguing, the characters often fall flat and their dialogue is hard to imagine taking place even in a futuristic setting:

"My earliest memories are of CP^4 -- that's a Kaehler manifold that looks locally like a vector space with four complex dimensions, though the global topology's quite different. But I didn't really grow up there; I was moved around a lot when I was young, to keep my perceptions flexible.”

“I only used to spend time in anything remotely like this" -- he motioned at the surrounding more-or-less-Euclidean space -- "for certain special kinds of physics problems. And even Newtonian mechanics is easier to grasp in a symplectic manifold; having a separate, visible coordinate for the position and momentum of every degree of freedom makes things much clearer than when you cram everything together in single, three-dimensional space."