The story moves forward on two fronts, earth-bound and space-bound encounters. It expands on the aliens hierarchical caste system and Darwinian approach for advancement. We also find out more about their technology and motivations for the human cloning program. The battle encounters both on earth and in space are exciting and often have unpredictable outcomes that adds to the heightened interest in the follow-on unfolding of events.
Very much interested in what follows in book 3 after the final unexpected revelation at the end.