The 1st adventure in this new series. With her famous father and brother in Africa on a research project, Sandra Swift felt she had a full plate with helping to run Swift Enterprises. But then she receives a visit from two FBI agents who present her with a diary written by her grandfather: Barton Swift. Fifteen years before he had disappeared when the airship he had been traveling in had crashed somewhere in South America. The diary is the first bit of solid information to have surfaced. Armed with this new knowledge, and desperate to find out more, Sandy decides to immediately investigate and sets out for Ecuador, accompanied by best friend Phyllis Newton, and by new arrival "Bingo" Winkler. In Ecuador they encounter secret agents, double-crosses, corporate conspiracies, ghostly apparitions and threats both above and below the surface of the ocean as they try to uncover answers concerning the fate of Barton Swift.