Episode: Black Gold. A visiting professor inspects the gold the Germans produced and gives Tom and Polberry the bad news that it's all fake. When Wing Commander Rogue confronts the German scientists they tell him the sunken Spanish galleon was a story they made up, but in reality they suspect instead that the island has huge oil reserves. They fly out to sea to show that they have an oil rig heading towards the island. Before drilling starts the team need to get rid of treasure hunters by convincing them that all the gold finds are fake.