Framton Nuttel does not tell Vera about his nervous problems, but he explains them to Mrs. Sappleton when she arrives.
"The doctors agree in ordering me complete rest, an absence of mental excitement, and avoidance of anything in the nature of violent physical exercise," announced Framton, who laboured under the tolerably wide-spread delusion that total strangers and chance acquaintances are hungry for the least detail of one's ailments and infirmities, their cause and cure.
It is because Framton wants complete rest, an absence of mental excitement, and an avoidance of anything in the nature of violent physical exercise that the description of his headlong retreat at the end of the story is ironic and funny even though it is purely descriptive. He will not have "complete rest" again for a long time. In fact, he may not be able to sleep at all. He has plenty of mental excitement from believing he has seen three ghosts approaching the house with guns and fearing that they might be chasing him. And instead of avoiding physical exercise, he is described as running out of the house and far down the road. The sentence about the cyclist having to run into the hedge to avoid a collision is intended to establish that Framton does not merely run out of the house but that he keeps on running.
The whole incident is orchestrated by Vera, who is twice described as a "self-possessed young lady." She tells Framton her story in a very serious manner, appropriate to ghost stories. She makes him believe that her aunt is insane because of losing her husband and two brothers three years ago when they were "engulfed in a treacherous piece of bog."
Vera is not only a story-teller but an actress. Framton is unnerved when Mrs. Sappleton says, "Here they are at last!" But what really makes him believe he is seeing three ghosts is Vera's performance at that moment.
The child was staring out through the open window with dazed horror in her eyes.
Vera has been self-possessed up to this point. But she has been planning to act horrified when she sees the three hunters approaching in the deepening twilight. The reader still doesn't realize that Framton is being hoodwinked until Mr. Sappleton speaks to his wife, which is after Framton's headlong retreat.
"Here we are, my dear," said the bearer of the white mackintosh, coming in through the window; "fairly muddy, but most of it's dry. Who was that who bolted as we came up?"
The only character who finds the incident amusing is Vera. We can imagine an innocent-appearing fifteen-year-old girl faking a look of "dazed horror" and really enjoying her own performance. The ghost story could have been told to Framton Nuttel by any kind of character, such as an eccentric house servant, or an elderly relative, or another visitor, but the choice of a teenage girl was perfect. She is bored. Being a girl, she can't go hunting with the males. She doesn't like being forced to play hostess to strangers. She probably regards Framton as a pain in the neck. She is all too familiar with the household routine involving the three men returning for tea through the open window, while the housebound females wait to hear about their adventures and heroism. She is imaginative. She finds that she has to talk about something with this silent visitor, so she makes up a story. Perhaps she wouldn't be sorry if the three macho hunters actually did get sucked down by a bog someday.