A plot to steal a top-secret instrument vital to the United States space program poses a challenging case for Frank and Joe Hardy. After rescuing a South American stowaway who mutters a warning about "Footprints " and then vanishes, Frank and Joe discover that documents belonging to their famous detective father are missing and that footprints linger under a window. The young detective's search for the diabolical mastermind of the "Footprints" spy ring takes them on a flight to a group of islands off the coast of South America.
| ISBN: | 9780448089126 |
| Publication date: | 1st February 1933 |
| Author: | Franklin W. Dixon |
| Publisher: | Grosset & Dunlap an imprint of Penguin Young Readers Group |
| Format: | Hardback |
| Pagination: | 192 pages |
| Series: | The Hardy Boys |