Stefano, the son of a wealthy businessman, meets a beautiful woman named Lidia while accompanying his father to a meeting with a cardinal. He pursues her through the streets of Venice and a romance develops. Upon returning from an overseas business trip, he is informed that Lidia has been killed in an accident. Soon afterwards, he thinks he recognizes her at a building site, but the woman claims to be a reporter who is obviously involved with gangsters. Furthermore, all evidence of Lidia's death has now been obliterated. Stefano continues to investigate the mystery, uncovering family intrigues.