Red Star (The Triple Stars, Volume 2). The Triple Stars Trilogy, #2

The return of an ancient galactic threatSelene and Ondo piece together the secrets of Concordance's ascension to galactic domination, and the truth of what it was Vulpis encountered at the heart of the galaxy three hundred years previously. They uncover an ancient threat to all life - a threat that Concordance seems intent on reawakening to complete its genocidal aims. But they also follow another trail - one left for them by someone or something unknown, a hidden intelligence seemingly guiding them to hopes of a possible salvation.
But each time they unearth a new fragment of the puzzle, Concordance are waiting, its ships and miraculous technology unleashed against them.