Die drei ???: Das Gold der Inkas

A slow day in Rocky Beach sends the three detectives to the local historical research institute — ostensibly so Peter can do research for a school presentation on Spanish gold transports, but mainly because they have nothing else to do. At the institute they run into Commissioner Reynolds and make an unexpected find: an old family chronicle that points to a lost Inca treasure. The trail leads to a sunken gold galleon, a diving expedition, and eventually the clutches of Panamanian criminals who have spent years protecting secrets about old pirates, gold routes, and a mysterious oath that connects everything.