Frank and Joe Hardy become involved in a case affecting national security when Joe dials a wrong telephone number and gets the Pentagon. Two words- "Bombay Boomerang"- that the boys hear before the line goes dead plunge them into a whirlpool of danger and intrigue. At the same time, Frank and Joe must save their father from a murderous gang stealing mercury shipments in the Baltimore harbor. With clues linking the mercury thefts to the top secret Super S missile mysteriously stolen from a government arsenal. In a race against time, the three Hardys foil a diabolical scheme to create widespread havoc in the United States.
| ISBN: | 9780448089492 |
| Publication date: | 1st January 1970 |
| Author: | Franklin W. Dixon |
| Publisher: | Grosset & Dunlap an imprint of Penguin Young Readers Group |
| Format: | Hardback |
| Pagination: | 192 pages |
| Series: | The Hardy Boys |