The TDF Marco Polo embarks on its maiden voyage outside Earth's solar system, leading to the discovery of an extinct civilization destroyed by orbital bombardment. Deep underground is a mysterious library of alien secrets.

The Terran Republic unravels the clues, forcing its politicians, scientists, navy, and marines to engage in an epic journey of space exploration, space battles, and combat behind enemy lines. They must rally their forces to defend the Earth as they discover The Others are coming.