An awkward girl and her genius preschool brother are swept into the intergalactic war of good and evil as they try to bring their scientist father back from a prolonged absence. They're joined by a neighborhood teenage boy with his own special talents.
Led by three supernatural creatures who steer their adventure, the children encounter many new and different creatures. They also learn to recognize their own strengths and the good in the world.
I enjoyed the book quite a bit, but reflect that I probably would not have enjoyed it as a child (I hated science fiction). I'm certainly glad that I'll understand the references now, as this book is considered an essential classic in the canon of children's literature.