From the US to Nepal, author J. Bradley Wigger travels five countries on three continents to hear children describe their invisible friends-one-hundred-year-old robins and blue dogs, dinosaurs and teapots, pretend families and shape-shifting aliens-companions springing from the deep well of childhood imagination. Drawing on these interviews, as well as a new wave of developmental research, he finds a fluid and flexible quality to the imaginative mind that is central to learning, co-operation, and paradoxically, to real-world rationality. Yet Wigger steps beyond psychological territory to explore the religious significance of the kind of mind that develops relationships with invisible beings. Alongside Cinderella the blue dog, Quack-Quack the duck, and Dino the dinosaur are angels, ancestors, spirits, and gods. What he uncovers is a profound capacity in the religious imagination to see through the surface of reality to more than meets the eye. Punctuated throughout by children's colorful drawings of their see-through interlocutors, the book is highly engaging and alternately endearing, moving, and humorous. Not just for parents or for those who work with children, Invisible Companions will appeal to anyone interested in our mind's creative and spiritual possibilities.