When Mark and Heather Smythe saved Earth from the conquest-hungry Kasari Collective, they thought their work was done. But the world's vast new government continued its quest to make extraterrestrial contact. And now, as a new gateway is activated to welcome the Kasari, whom world leaders take to be benefactors, only the Smythes stand a chance of countering their planet's invasion and subjugation by a race of ruthless conquerors.
Years after their failed first mission, the Kasari have returned, bearing irresistible promises while concealing insidious plans to enslave humanity. But not if the Smythes - along with fearless CIA agent turned mercenary Jack Gregory and his partner, Janet Price - can help it. From the world's last stronghold, they take the fight to enemies both earthling and alien - even as their comrades-in-arms join the warrior Koranthians in battling the Kasari on a far-off planet. But the greatest danger lies within Earth itself, where an ancient artifact prepares to summon doom from another world.