Who, besides Mr. Nuttel, is the victim of Vera's hoax?
It might be said that Mrs. Sappleton is also the victim of Vera's hoax, but that would depend upon what happened after Framton Nuttel fled from the house. He might report to other people that the woman was insane. That seems unlikely, however, because he would be required to tell about the whole incident. If he did that he would find out that the three "ghosts" he thought he saw were still very much alive, in which case Mrs. Sappleton was perfectly sane in expecting them to come home and in leaving the window open. It seems unlikely that Nuttel would not relate his experience to his sister and that she would make inquiries of the minister with whom she stayed when she was in the area. Vera herself might become the victim of her own hoax in that case. Everyone would realize that she had played a cruel trick on their poor, neurotic visitor and that she had also misrepresented her aunt as a lunatic.
"Here they are at last!" she cried. "Just in time for tea, and don't they look as if they were muddy up to the eyes!"
Framton shivered slightly and turned towards the niece with a look intended to convey sympathetic comprehension. The child was staring out through the open window with a dazed horror in her eyes.
Vera would be subject to some form of punishment--or at least a severe scolding from more than one of the members of that family. That might not discourage her from frightening other visitors with the same ghost story in the future, since it had been such a big success with Framton Nuttel. The same scenario seems to be repeated practically every night. Mrs. Sappleton leaves the big French window open for the three hunters, and they return at about the same hour for tea. Bertie sings the same awful song with the words:
"I said, Bertie, why do you bound?"
It is a little bit like the movie Groundhog Day in which the same things keep happening every day. The entire family, including Vera, might be somewhat victimized by the girl's hoax if word got around in this uptight neighborhood that the entire family was conspiring to frighten visitors out of their wits with ghost stories and bizarre behavior. It seems possible that Nuttel might have gotten the idea that the whole family was in on the hoax and had actually rehearsed it.
On the other hand, if the family's reputation was not compromised, Framton Nuttel's sister, who does not appear in the story, might be slightly victimized because she might not be welcome to return to the rectory or the neighborhood because of her relationship with a man who was obviously a lunatic. Friends and neighbors of the Sappletons would be more likely to sympathize with them than with a couple of strangers who lived in London.
One could argue that the reader him/herself is duped by Vera. The story is told mostly through dialogue; the reader is never given any insight into Vera's thinking, so the reader thinks what Mr. Nuttel thinks. The narrator does not reveal anything to the reader (or Mr. Nuttel) until the hoax is complete. When the dialogue shifts to narration, the narrator describes Vera's outward reaction (her "acting"); not what she is thinking.
The child was staring out through the open window with dazed horror in her eyes.
When Mr. Nuttel leaves in a hurry, Vera decides to continue the hoax and invents a new story about Mr. Nuttel himself. Therefore, Mrs. Sappelton, her husband, and her two brothers are also victims of Vera's hoax. When Mr. Nuttel leaves as if "he had seen a ghost" (according to Mrs. Sappleton), Vera makes up another story that Mr. Nuttel was terrified of dogs because of a terrible experience on the banks of the Ganges. By the end of the story, Vera has fooled everyone. The last line confirms Vera's tendency to lie - that "romance" (imagination) was her "specialty."