"Nothing must remain behind. Whole cities must vanish without a trace, as a curl of smoke disappears, leaving no more than the wisp of a memory."
Having failed in their attempt to accelerate the culture and technology of an Early Bronze Age civilization on Earth, the atLan are about to return to their home planet - but not before annihilating every vestige of their presence with fearsome weaponry. Tahryn, one of their most promising protgs, has reason to regret their departure, since it will mean an end to his forbidden relationship with an atLan woman. In the story, as narrated by Tahryn many years later, he ponders where his destiny would lie - with the woman he loves, but cannot have, or the one he has, but cannot love.
When a rebel atLan faction seeks instead to remain by destroying those preparing to return home, Tahryn finds his life at risk, caught up in a cataclysmic struggle between warring aliens that will lead him through the maelstrom to his destiny.