In Venice, Daniele runs a dredge that is digging a new lagoon canal, called "The Canal of the Angels." He is married to Anna, who is much younger than him, and the two have a child, Andrea. Due to a work injury, Daniele is unable to accompany his wife to a party. There Anna meets "the captain," a young sailor who, while waiting for his dreamed boarding on a large ocean liner, works as a ticket-taker on the vaporetti that run in Venice. The captain is attracted to the woman and she, too, is not insensitive to the man's charm, so much so that the two at the end of the party embrace and kiss, not realizing that little Andrea is watching them from afar. Now Andrea is experiencing a bad relationship with his mother and this makes him ill. Anna is torn between family affections and her relationship with the young sailor. It will finally be the captain who decides to leave on the first steamer to depart, even though it is not the luxurious liner he dreamed of.