Choices were made
Sergeant Sanda Greeve wakes alone in the medical bay of a strange ship. Worse, it's an enemy ship and the only other inhabitant is the sentient artificial intelligence who runs the ship, The Light of Berossus, aka Bero. And that's not the worst news she's about to hear. Bero shows her that Ada Prime (Sanda's home planet) and Icarion (their enemy) have both vanished from the galaxy, blown up 230 years ago during the war that left Sanda wounded. Sanda had been in stassis in a life pod until Bero, who has been alone for years, found her.