Long Pond Cay, in the Bahamas, is a magical white-sand island. Twelve-year-old Trey and seven-year-old Lou love to visit its loneliness. But one day the magic becomes nightmare, and suddenly they are in another world, strident, polluted and overcrowded - where little Lou is hailed not as a mute Bahamian boy but as the mythic hero Lugh, born to bring terrible destruction and renewal. Carried between worlds, the children risk their lives not only to save the alien world, but to ward off a new parallel threat to their beloved Long Pond Cay. The forces of myth and nature explode together in an amazing climax.