In the year 2432, humans think they are alone in the universe. They're wrong.
Commander Noa Sato plans a peaceful leave on her home planet, Luddeccea, but winds up interrogated and imprisoned for her involvement in the Archangel Project. A project she knows nothing about.
Professor James Sinclair wakes in the snow, not remembering the past 24 hours or knowing why he is being pursued. The only thing he knows is that he has to find Commander Sato, a woman he's never met.
A military officer from the colonies and a civilian from Old Earth, they couldn't have less in common. But they have to work together to save the lives of millions - and their own. Every step of the way they are haunted by the final words of a secret transmission: The archangel is down.