Couloumbis gets the suspense going at a high pitch from the start of this gripping novel, quite a dramatic departure in theme from her Newbery Honor book, Getting Near to Baby. In the first chapter, narrator Casey describes her morning exchange with her stepmother, Sylvia; by the second chapter, Sylvia is gone. The woman's sudden disappearance will be as unsettling and incomprehensible to readers as it is to the 12-year-old protagonist, who is now completely alone (her father has died). As this intriguing story progresses, the mystery of why Sylvia abandoned Casey becomes less relevant than the girl's struggle to fend for herself in her New York City apartment. Sixteen-year-old Paulie, the streetwise foster son of the building's super, is the only one who has figured out that Casey is living alone. He hatches a plan to help her get money for food and rent, but requires her to take part in a robbery. Besides battling with her conscience, Casey must make hard choices about whom she can trust and whom she should protect. She remains loyal to Sylvia, although it seems unlikely she will return. At the same time, Casey becomes increasingly reliant on Paulie. Rather than drawing clear lines between villains and heroes in this modern-day survival tale, Couloumbis invents realistically complex characters, whose morals are tested by fear and desperation, and a world in which right ultimately defeats wrong. Ages 10-up. (May)