The largest treasure haul ever found underwater makes headlines worldwide, but soon, attention turns to who really wons the half-billion dollar treasure of the mysteriously code-named "Black Swan"?

Fearing one of their most prized historical treasures has been uncovered, the Kingdom of Spain takes on salvage company Odessey Marine Exploration for the treasure.

As the two sides fight it out in a tampa court, it soon becomes clear that not all is what it seems... Using unique techniques developed for the series Drain the Oceans, the extent of the treasure on the seabed is revealed for the first time, and the debate of 'who owns history' is taken to a whole new level.