For several hundred years there's been a near mythical story in Buenaventura - about a large treasure of gold that can be found in the so-called "lost city". Eva Bergeron, a beautiful German archeologist, has an old map and hires Rio to help her look for the treasure. However, Carlos Rey De Lupos, the Minister of Antiquities, wants the map for himself and kidnaps Eva. Rio prepares to rescue Eva but finds out that she hasn't been completely honest: she's no archeologist...