Timothy Zahn has crafted a fresh, suspenseful tale of an alien feud in New York City that is about to spiral out of control. The Greens and Grays have been living in the shadows of New York for seventy-five years. Each group believes that it is the sole survivor of a devastating war between these two ancient enemies. When the two groups discover the presence of their enemy, they come to an uneasy truce, which depends on the sacrifice of twelve-year-old Melantha Green. But at the last moment, Melantha is rescued and thrust upon an unsuspecting young married couple, Roger and Caroline Whittier. Armed with uncanny powers and advanced technology, the truce coalition is desperate to get Melantha back. But the Whittiers have vowed to protect her, and they enlist the aid of a sawy NYPD detective and a former Ellis Island clerk who's known about the aliens since they first came to New York. The stakes are larger than they can know, as a war threatens to explode that could annihilate both groups and destroy much of New York City as well. Unlikely allies, unlikely heroes, they have just one week to prevent a war unlike any the world has ever seen.