The intricate and action-packed sequel to New York Times bestseller and master tale-spinner Eric Flint and K.D. Wentworth’s ground-breaking Course of Empire. Humanity is first subjugated by haughty alien colonizers calling themselves the Jao when Earth is unexpectedly attacked by the implacable and nearly-unstoppable Ekhat, exterminators of all intelligent life not their own. Now the fragile Human-Jao alliance is put to the test. A devastating encounter with the Ekhat in a distant nebula reveals a powerful alien society that may hold the key to defeating the Ekhat once and for all. There’s one big problem: they utterly loathe humanity's ally, the Jao. And why shouldn’t they? It was the Jao who drove them into hiding in the first place. Once again, everything depends on those innovators and idea-generators, the humans, to quell a brewing war and forge a tripartite alliance of very different species―or be blasted to empty cinders if they don’t succeed.