When Professor William Waterman Sherman leaves San Francisco in a hot-air balloon, he intends to fly across the Pacific Ocean. Instead, through a twist of fate, he lands on Krakatoa, a legendary island of unimaginable wealth, eccentric inhabitants, and fantastic balloon inventions. Once Professor Sherman learns the secrets of Krakatoa, he must remain there forever - unless he can find a means of escape.

"William Pene du Bois combines his rich imagination, scientific tastes, and brilliant artistry to tell a story that has no age limit." - The Horn Book