In this fairly convincing portrait of a teenager coping with her mother’s onset of Alzheimer’s disease, Sylvie, 14, has always been an excellent student, even through her parents’ divorce. Her grades begin to slip, however, as her beautiful, talented mother, Marianne, starts behaving in dangerously crazy ways. She can’t tell the time, has forgotten how to cook, and their usually fastidious apartment has grown filthy. The book opens on the day Sylvie finds Marianne perched high on the balcony of their tenth-floor Winnipeg apartment, apparently ready to jump. Sylvie thereafter attempts to cope on her own, ignoring school, her piano lessons, and her best friend, Marissa, who is coping with her own abusive, alcoholic mother. Angry and embarrassed, Sylvie allows an elderly neighbor, Mrs. Rathbone, to help; discovers a sympathetic listener in a schoolmate, Paul; and finds that her father is more than willing to rejoin his family as they learn more about Marianne’s diagnosis. Sylvie’s initial confusion is authentic, and often heart-stopping; Moore makes vivid how much of a stranger Marianne becomes to her daughter. Less coherently limned are Sylvie’s external reactions. While there are hints that she is dressing provocatively because of her mother’s illness, the connection never becomes clear, while her early reliance on Mrs. Rathbone’s interference is not in line with the rest of her furtive behavior. (Fiction. 11-13)