Pia, an eight-year-old girl whose family had emigrated years back, arrives in the Maltese islands together with her unkind stepmother Raquel and her best friend, a dog named Tinkerbell, to be present for the reading of her Maltese grandmother's will. Raquel warns the girl that unless she gets to inherit property and money, Tinkerbell will have to be put down due to financial reasons. However the only person who gets to inherit the grandmother's vast fortune is her adopted son, Ino. Pia meets her cousin Sandro, an eight-year-old geek who is the uncool version of MacGyver thanks to his resourcefulness. After hearing about the legend that the Golden Calf mentioned in the Bible is hidden in the Maltese islands and so as to save the girl's beloved pet, the two children embark on a treasure hunt full of adventures. Some of their adventures take place underground, where they unearth a number of family secrets. With Ino trying to stop the children from finding the treasure and Sandro ending ...