As in her debut novel, Sights, Vance serves up a potent combination of quirkiness, girl power—and dire menace. Two very different girls alternate as narrators. Birdie, 13, is the highly indulged but likable only child of intellectual Oregon parents who decide to spend a year on a Caribbean island. Morgan, 17, has been raised at sea by her Norwegian parents and her speech, she explains, "is marked from being a reader more than a speaker, and from never having lived in any of the countries whose languages I understand." Confident Birdie believes she has been through "a lot,
" listing among her "hardships" that "my parents spend too much time thinking about me." By contrast, the anachronistically voiced, dour Morgan must struggle for survival: as her hard-drinking parents soak up still more rum at a bar in Panama, she sails away without them ("Now I circle the ocean alone, the child of a Viking mother"). The threads connecting these opposite characters remain mysterious for a lengthy interval—during which Birdie is kidnapped by a sociopath calling himself Nicholas, to whom Morgan turns for help when she needs false papers to secure her independence until she comes of age. The girls' fates intertwine in the last 50 or so pages, when the pace quickens dramatically. Neither narrator has the offbeat charm of Sights's Baby Girl and the plot lines here require more energy to pursue. A message about positive thinking, loosely threaded throughout Birdie's narrative, resounds clearly at the end. Ages 12-up. (May)