Treasure hunters Remi and Sam Fargo are in Washington DC looking for the final clue in a puzzle more than a decade old - a dangerous mystery which originally led to their teaming up. For ten years ago, a chance meeting that threw Remi and Sam together leads to the pair diving for ancient sunken wrecks off the Greek coast. But when a secretive billionaire decides he doesn't want anyone diving in the seas near his operations, the pair find themselves in deep trouble. Only when they learn that the legendary riches of Croesus may have been lost in these waters do they understand who and what they were up against. Suddenly, finding the treasure becomes less important than making it home alive...