In today's world, Braxton Thorpe suffers from incurable cancer and arranges for his head to be cryogenically preserved upon his death--an Icicle. He awakens a century later as an electronic upload—A Tensor Matrix.
Working with colleagues, he moves out into the Solar System where he discovers another electronic entity, the Oort, and learns about an existential threat to the Solar System. Aliens who attacked the Solar System in the distant past are returning to do it again. Working with the Oort and cooperating nations of Earth through the Oort Federation, Thorpe and his allies thwart the aliens' scheme.
With the alien invasion behind them, Thorpe and his colleagues govern the Solar System through the Oort Federation. Its various players are Thorpe's Phoenix, his colleagues' Ogden Enterprises, and their collective nemesis, Isidor Orlov and his Udachny Enterprises. Thorpe and Orlov follow parallel paths to FTL drives using different technologies. Both groups travel to the alien star system where Thorpe allies with the Asterians, and together they overcome Orlov. Thorpe and the Asterians work together to open the galaxy.
With the participation of the Oort and the Asterians, Thorpe prepares to journey outside the galaxy in the Starship Andromeda, searching for a point in the universe that his scientists suspect is an intersection of our universe with a parallel universe. The first stop in this journey is the star Ran. The main planet, Arcan, is home to a saurian race with incipient space travel. The saurians have hidden themselves from the rest of the Galaxy, fearing contact with the superior races they know about. The voyagers get pulled into two local wars, before they move on, taking a contingent of Arcans with them.
The next stop is the triple-star system Keid, where they discover a derelict Dyson Sphere. They are attacked by microbots that are scavenging part of the sphere to costruct another part. They find several primative sapient species inside the Dyson Sphere, and meet digital uploads of the race that built the sphere. They determine that the sphere’s star is about to produce a superflare that could destroy all life inside the sphere and may destroy the sphere itself. They mount a rescue attempt to save the uploads and sapient races.
Andromeda continues its voyage of discovery to the Cold Spot in the Cosmic Microwave Background. A century earlier, human scientists had determined this to be the convergence of our universe with a parallel universe. Along the way, the voyagers encounter several sapient species—some friendly, some not so friendly, and once again, they must deal with Isidor Orlov and Udachny. They persevere and eventually reach and penetrate the convergence, where they meet Humans much like themselves, with consequences that impact both universes.