Larth is an archaeologist fond of Etruscan civilization, following the traces of a famous royal tomb. Vasco is an area hotelier who has enriched himself by raiding his tombs and selling their treasures. One night Larth, while intent on his excavations, hears shots coming from the museum and sees a red car moving away. The next morning he learns that the caretaker was killed and important works of art were stolen. Larth continues his research, also stimulated by his wife Eleonora and his friend Albert, an expert in archaeology, to whom a Swedish professor asked for advice to begin a series of excavations intended to discover the royal tomb. Meanwhile in the life of the archaeologist comes Tania, a beautiful thirteen year old, Vasco's niece, who disturbs the mature scholar. Tania would like to seduce Larth despite the Eleonora noticing her moves; but man does not give in to the girl. His tranquility and his relationship with his wife, however, are in crisis. Vasco, with some accomplices, would like to get to the king's grave to make money by selling the finds. Larth enters first in the tumulus and among the various works of art he sees the sarcophagus of Thannìa, the famous Etruscan princess he had dreamed of; his body is intact and looks amazingly like Tania. But it is only a moment: the vision disappears and in the eyes of Larth remains only a skeleton covered with dust. Albert and Vasco also enter the tomb; the latter, to touch the findings carelessly collapses once the basement and remains stuck under the rubble with a leg. It is saved with difficulty; but Larth disappointed, blow up the whole tomb with its treasures.