About “The Secret Warning”
A cryptic warning message triggers the Hardys' investigation into a dangerous plot. They decode the secret to prevent catastrophe.
Book details
- First published
- 1938
- ISBN
- 9781557092854
More: Wikidata · Open Library
A cryptic warning message triggers the Hardys' investigation into a dangerous plot. They decode the secret to prevent catastrophe.
More: Wikidata · Open Library