Carlo is having a normal day at work, ferrying some Japanese tourists out of the halfway submerged Venice to another fully abandoned city. At the site, he and the tourists put on their scuba gear and dive into the church that is the goal of the Japanese tourists. All is going well until they find a mosaic of Madonna, sparking the excitement of the tourists. When they emerge from the water, the tourists tell Carlo that they are going to stay all night to remove the mosaic, and ask him to stay as well. Carlo is angered by their plan, saying that their permit from the Italian government isn't valid as Venice is the Republic. But he doesn't stop them, instead just leaving them there with a promise to pick them up in the morning.
Sailing back home, Carlo is upset, and gets caught in the storm he had seen brewing on his way to the site. It is a far worse squall than he had anticipated, and he thinks he is going to die—he almost does. But somehow, he gets washed up close to a campanile, an Italian bell tower, and times his save perfectly by hooking his boat hook into the tower and leaping into it himself. Inside, he meets an old woman, someone who refused to evacuate her home, it seems. She looks to be nearly blind and certainly a little bit senile as she blabbers on about showing what a person can bear and not die. No matter, Carlo has a safe place to sleep for the night as he waits out the storm.
In the morning, he can't find the old woman anywhere, but figures he'll come back another time to say goodbye. He makes it home across a placid Lagoon, to his worried wife. He tells her the story, and then grabs a few hours of sleep before she wakes him up to go get the Japanese tourists.
"Let them take what's underwater," says his wife. And Carlo goes off to get the tourists, understanding that yes, what was truly left of Venice was still afloat.