An American special agent embarks with amazing effort on a mission to recover vital material for the United States'' defence. It was believed that the mighty ''unsinkable'' ship contained a vital material, which could be used to make the United States impregnable to atomic attack. The ship is down too deep for divers, so the only solution is to raise it and the Herculean project must be managed in absolute secrecy – despite the extreme rigours of the climate, deadly interference from a rival nation, and the need to invent technology never before conceived. The extraordinary task is interlaced with the stories of the people and the forces working against them.