Slim has recently chosen to live in L.A. with her dad and his ""friend"" Larry instead of with Mom and her third husband, whose job compels frequent moves. Mom doesn't know -- and Slim is determined she won't find out -- that Dad has AIDS. Dad, an endearingly witty actor, is anxious to keep his daughter with him, and the responsible Larry puts his dying friend's needs first. Thus Nelson (The Beggar's Ride, 1992, etc.) sets up a 12-year-old as observer and recorder of her father's last months. A support group with other young people (notably Isaiah, 11, whose pregnant mother contracted AIDS from his dad, who's now dead) provides contrasting scenarios and a warm community whose vulnerability is highlighted when nco-Nazis invade their fund-raising fair. A mishap-plagued trip by the whole crew to the mountains for a fraudulent ""miracle"" in which most of them have little faith anyway becomes a companionable journey capped by a moment of transcendent beauty when fog lifts to reveal a meadow of wildflowers. Nelson's characters are rich in affection and individuality. If Larry is almost too good to be true, his courage and self-denial free Nelson to focus on Slim's feelings in a well-developed series of poignant incidents. Good, but for a more imaginative approach to a parents' death from AIDS, see Porte's Something Terrible Happened (p. 1414).