The UFS Phoenix is finally homeward bound. On the way is Tuki Station, in barabo space, hit just now by a force of sard ships, working in concert with a larger invasion from alo space. An alo and deepynine fleet has attacked, and humanity's forces are in turmoil despite all of Phoenix's efforts over the past three years to prepare them.

Nia leads the assault, Styx's old AI queen nemesis from the Drysine/Deepynine War, the greatest armed conflict in Spiral history, 25,000 years ago. But what does Nia seek? Is she after the drysine data-core, which Phoenix recovered nearly three years ago? Does she pursue members of the Debogande family visiting Hoffen Station, as a way to get at Phoenix's captain personally? And if she's making a full-scale attempt to remove humanity as a strategic threat, why do her battle plans look so odd?

Nia is the greatest synthetic military mind in history, save for Styx. Human Fleet desperately needs Styx's help, yet Supreme Commander Mazungu is terrified of ceding her, and Phoenix, too much power. And now Styx herself has competition, as Phoenix's shipboard AI Shali has just acquired a massive analysis program from reeh space, designed specifically to map Nia's mind and beat her.

But can Nia be predicted, before it's all too late?