This book is an adventure story about the exploits of Frank Reade Jr. Reade is a famous inventor of steam, electrical and mechanical inventions of various kinds. He had previously completed building the greatest air-ship he had ever conceived of, and had added a crown to the glory of his great talent. A chance encounter with the wealthy Mexican Juan Zamora promises to yield great fortune to him. Zamora asks Reade to lend him his air-ship so as to effect a rescue of his young son who has been captured by the dreaded American outlaw called Captain Diavolo. And Reade agrees…