Katherine Alice Applegate is simultaneously one of America's most famous authors and one of America's most mysterious.

She guards her privacy, as does her publisher, Scholastic, which has brilliantly marketed her Animorphs and Everworld series with astounding success. Applegate was already a well-established writer of books for young readers, mostly romance novels, when she proposed the Animorphs series to Scholastic, where the proposal was met with enthusiasm. She wanted to write a series of books that showed how the world might look from the perspectives of different animals; the result has been a series of fascinating novellas for readers from late elementary school to junior high school.

After moving around the United States several times, the Michigan-born writer now resides in Minneapolis. Over a hundred of her books have been published, and she has written them at an amazing pace. Begun in 1996, her Animorphs...