Orphans Albert and Victoria Wiggins leave the orphanage there they have been living since their parents' deaths and go to live on the farm of their inventor uncle, Sir Joshua Cranberry.
A report from Ollie Bergmann, the Centauri Network's member in Hamburg, about a mysterious illness affecting endagered white-tailed eagles on Rügen Island takes Sir Joshua to Germany.
Neville Savage's search for a sunken Spanish galleon off the island of Mallorca attracts the attention of the Centauri Network when his sonar tests drivers all the fish from the bay.
Before returning to Australian, Sir Joshua, Albert and Vicki stop in Yorkshire England to visit his aunt Edith who is having trouble with her neighbour.
Sir Joshua, Albert and Vicki return triumphantly to the farm in Australia knowing that although Savage remains at large, all of his accomplices have been arrested.