How does Vera's story about Mrs. Sappleton's husband and brothers affect Mr. Nuttel's internal conflict?

Framton Nuttel suffers from a nervous condition and is possibly a hypochondriac. He may have a legitimate neurological condition and it may be psychosomatic. In either case, he is quite easily affected by Vera's story. Vera tells the story that her aunt's husband and brothers left through the window three years ago and never returned. They were presumed dead. Vera ends with, "Do you know, sometimes on still, quiet evenings like this, I almost get...

Framton Nuttel suffers from a nervous condition and is possibly a hypochondriac. He may have a legitimate neurological condition and it may be psychosomatic. In either case, he is quite easily affected by Vera's story. Vera tells the story that her aunt's husband and brothers left through the window three years ago and never returned. They were presumed dead. Vera ends with, "Do you know, sometimes on still, quiet evenings like this, I almost get a creepy feeling that they will all walk in through that window—” 

When Vera's aunt walks into the room, Mr. Nuttel is relieved. However, Ms. Sappleton then tells him she expects her husband and brothers to return soon. Mr. Nuttel is horrified by this.

To Framton, it was all purely horrible. He made a desperate but only partially successful effort to turn the talk on to a less ghastly topic; he was conscious that his hostess was giving him only a fragment of her attention, and her eyes were constantly straying past him to the open window and the lawn beyond.

He tries to change the subject and relates that he is supposed to avoid all mental and physical exertion. Then the husband and brothers return and Mr. Nuttel leaves in a hurry. But it is Vera's story that sets up his horrified need to escape. One could argue that Vera is malicious in this practical joke. On the other hand, Mr. Nuttel is just too impressionable and too gullible. What are the odds that he would arrive on the alleged tragic anniversary? He never considers that this coincidence is suspicious. When he feels uncomfortable, he starts talking about himself and his ailments. Vera's story easily plays with his vulnerable and sensitive tendencies. Vera is a gifted storyteller/liar, but Mr. Nuttel's weak mental state makes it easy for her to fool him.