What do you find out about Vera at the end of "The Open Window"?
In kind terms, we learn that "Romance was her specialty". In unkind terms, we learn that Vera is a habitual liar.
Mr. Framton Nuttel is introduced as a nervous man seeking a calm place to restore himself. He is waiting to speak to Mrs. Sappleton, in her house in the country, and until she arrives he is "entertained" by Vera, Sappleton's niece. She unfortunately launches into a story about how her father went hunting three years ago, leaving through an open window, and was lost in a bog with two other men and a dog. According to Vera, Mrs. Sappleton leaves that window open in the hopes that someday her husband will return.
Near the end of the story it seems, at least to Nuttel, that Vera's story is true, and Mr. Sappleton's ghost is approaching the house. Nuttel flees in fear, but rather than explaining that it was her story which caused him to run, Vera simply launches another, equally fantastic story about Nuttel having once been hunted by wild dogs. This reveals that Vera is perhaps a bit unhinged, and that Mr. Sappleton is very much alive.