The human and atevi residents of Alpha Station, orbiting the atevi home world, have picked up a signal from an alien kyo ship saying that the ship is headed toward Alpha. Five thousand of the inhabitants of Alpha are human refugees from Reunion Station, which was abandoned when a single kyo ship attacked without warning and destroyed a major section of the station. Bren Cameron, human emissary of Tabini-aiji, the powerful atevi leader on the mainland below and appointee of the human president on the island nation of Mospheira, is sent up to deal with the panicked refugees and the incoming alien ship.