The Hardy Boys, brothers Frank and Joe Hardy, are fictional characters who appear in several mystery series for children and teens. The series revolves around teenagers who are amateur sleuths, solving cases that stumped their adult counterparts.
The Secret of Pirates' Hill is Volume 36 in the original The Hardy Boys Mystery series published by Grosset and Dunlap. Hired by a mysterious businessman to locate an old Spanish cannon, the Hardy brothers and friends grow more and more suspicious as they encounter stolen cars and a mysterious man on a motorcycle. They eventually uncover the cannon and thousands in gold bullion after perilous underwater adventures.
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