Remnants of the Pegasus humans, originally from Earth and their newly acquired allies the BeNovans arrive in Alpha Centauri to escape the Krang. Two years is spent rebuilding the Galactic Star Force with new starships discovered when fleeing Pegasus. Two years to plan for a rescue of anyone left behind in Pegasus. At the same time scouting missions are sent to SOL to discover if there are any humans left there from the last world war.

A strong society is found in SOL though they have no light speed capability, they were limited to intra-solar flights. Life had survived the war and existed on Earth, Earth's moon, and Mars. While scanning SOL, Jack L. discovers an invasion by a species the KroMach bent on destroying all life in SOL. KroMach is lizard-like creatures bent on dominating everything in their path. Jack L. intervenes providing the humans of SOL with a brief respite from destruction.

Those in Alpha Centauri are now faced with a need for two fronts, one rescuing in Pegasus and the other keeping SOL free of KroMach. The effect would split Galactic Star Force ships to supporting two fronts. Pegasus was closet to Alpha Centauri Hearts, rescuing those left behind. Allowing a potential adversary into SOL only four light years from them couldn't be allowed, beside they were cousins.