Koss's (The Girls) astute and affecting novel treats tragic themes with an invigoratingly tart tone. The narrator, 11-year-old Robyn Gittleman, is vacationing with her family in Vienna when their luggage is stolen. What bothers her most is the loss of her diary, a gift from her diary-keeping aunt, killed six months earlier in a traffic accident. Robyn's mother, who was with Aunt Beth in the car, remains so traumatized that she, like Aunt Beth, also seems absent. The entries in Robyn's replacement diary form the narrative: "Sometimes I want to yell at her, 'Who died in that crash? You or Aunt Beth?' " she confides. The various types of mourning the heroine experiences intensify against the Austrian backdrop, with Koss deftly incorporating moments suggestive of that culture's distinctive black humor (e.g., a tour guide shows off a famous crypt, saying, "Anyone care for tinned meat? Within these jugs are the vital organs… of members of the Hapsburg family"). The author also allows Robyn to consider, briefly, the Holocaust, which the girl's Austrian-Jewish great-grandparents, alone of their families, survived. The particularly insightful portrayals of Robyn's anger and internal conflicts find an almost ideal counterbalance in her mordant wit and candor—painful though her grapplings are, her emotional recovery manifests itself so gradually and lightly as to surprise readers with the force of its optimism. Ages 8-12. (Sept.)