After finding an American coin at Le Chameau's wreck site, Jeff MacKinnon must choose to either stay the course or chase a new mystery. Sonar reveals a potential wreck, but a cryptic clue suggests an even greater discovery hidden beneath the waves.

Jeff MacKinnon's team battles thick kelp, brutal currents, and a looming storm while searching Scatarie Island's coast. Just as the storm hits, they make a crucial discovery--a clue that could lead to the long-lost wrecks and hidden treasure.