The paradise is lost in the ocean
He found a can of a medicine that kills different types of bugs and parasites. Candy tells him the man who stayed in his bunk before was very clean and probably has a can as a precaution.
Answer:
I believe the theme of this story is that truth is sometimes better left unsaid[or "truth kills"]. Like in this story, the guy loved this woman and thought she had loved him back. He would have never thought that she would go out and try to deceive him. He would have lived happier, if he thought that she was still faithfully clinging and loving him silently even in death. Yet he was very oblivious and curious to know the truth of why she had died, and that truth eventually killed him.