ea. vol: (Stepping Stone Bks.). CIP. Random. 1988. PLB $5.99; pap. $1.95. Gr 2-4O'Diddy , formerly the imaginary friend of a young girl nicknamed Boon, has now become invisible to her because she no longer believes in him. O'Diddy tries, through various contrived situations, to make Boon believe in him again. Told in the first person, the story's writing style is corny and irritating, with too many asides and admonitions to readers to continue reading, to believe in imaginary friends, and to feel sorry for O'Diddy, none of which work. Set in Alaska, Silver is told by nine-year-old Rachel, whose father competes in dog sled races in the winter. She is given the runt of the litter of puppies born to her father's best sled dog, and she names him Silver. While her father is competing in the Iditarod, Silver is stolen by a mother wolf to replace one of her cubs who had died. Rachel rescues the pup and trudges home through the snowstorm, barely able to find her way. Safely home, she awaits word of her father, who finishes third in the dog sled race. This is a lively, thoroughly credible story emphasizing the loneliness and excitement of Alaskan living for a young girl. The strong and forceful female protagonist brings to mind Jean George's older and more sophisticated Julie of the Wolves (Harper, 1972) for more advanced readers. Hayden E. Atwood, Cape Elizabeth Middle School, Maine