Peril strikes during a daring dive as brothers Rick and Marty Lagina double down on their efforts to locate the original Money Pit with the most ambitious engineering operation in Oak Island history, while the fellowship of the dig is faced with a tragic loss of one of their own.

New, hard evidence of a European presence on Oak Island more than a century before the discovery of the Money Pit exhilarates the team, until alarming news threatens to shut down the entire operation.