Telepathic tree creatures on the planet Oomb have welcomed Ludi and Pedro Perez with open branches, to build a new life for themselves light years away from Earth. The Oombians are not so happy, though, with other humans' efforts to use their island-strewn paradise as a staging area for combatting an imminent extraterrestrial threat. Will the Perez family come to regret having gotten "raptured" sixty years into the future, despite their former struggles in north Philadelphia? And will plans for interplanetary war inadvertently lead to the annihilation of an entire civilization? Meanwhile back on Earth, a nihilistic scheme is fueled by the systematic walling off, worldwide, of the affluent from those less fortunate.