They were chosen as the best of humanity. Now they might end up being the last.

Project Nomad's grand vision of colonising the galaxy has shrunk to a desperate struggle to escape from an Earth racked by famine and bioterrorism. A ragtag band of scientists, farmers, and soldiers are the last of the settlers bound for mankind's first extrasolar colony on Opis, and they have one last chance to leave.

They've done a deal. They've traded the Ainatio corporation's instant communications research that made Nomad possible for permission to launch its ageing interstellar ship. The Asian-Pacific States, the sole threadbare superpower in a world of broken nations, are happy to let them go until an unknown informer betrays a secret: Solomon, Nomad's AI, is the remnant of a banned type of artificial intelligence that's already caused millions of human deaths. They have to ground the mission. He has to be destroyed.

But Solomon exists for one purpose. He's going to take his ideal humans to Opis, even if it means launching a war against APS.

As the situation on Earth spirals out of control, Captain Bridget Ingram has done a deal of her own, forty light years away in Nomad Base. The mission has new and unexpected neighbours, alien engineers who've offered to share an FTL technology that'll change the future of humanity. But they want something in exchange - protection.

The aliens haven't exactly told Ingram everything. But she's going to find out very soon who they need to be protected from, and why. It's too late to stay neutral and too late to abort the mission and head home. If she doesn't take the biggest gamble of her life -- one that could destroy the fledgling colony before it's even begun -- the rest of the colonists will never make it to Opis.

But even if they manage to leave Earth behind, Earth is far from finished with them. And the problems on Opis are just about to start.