"The Open Window" was written over a hundred years ago. Doctors knew very little about such things as "nervous disorders," "mental disorders," and "psychological disorders." There were no tranquilizers available, and doctors were hardly likely to prescribe liquor, opium or morphine. It was safe and commonplace to prescribe an ocean voyage or a stay in the country. There are several Sherlock Holmes tales in which the brilliant but eccentric and hypersensitive detective has left London seeking a rest-cure in the English countryside. One of the best of these is "The Adventure of the Devil's Foot."
Framton Nuttel is staying in the English countryside because several London doctors have suggested it, which shows how much doctors thought alike in Saki's time and how little they really knew about what we would now call neurosis. Framton appears to be a gentleman of leisure who can afford to consult multiple doctors and to travel anywhere he pleases and stay as long as he likes. It certainly seems logical that a vacation in a peaceful country setting would be good for anyone's frazzled nerves. Framton is probably suffering from too much of the kind of stress common to big cities, including noise, traffic, overcrowding, air pollution, and crime. He expects to meet a family of sedate, church-going country people but couldn't have entered a more unnerving environment if he had gone into a lunatic asylum. It is because he expects this family to be so humdrum that he is taken in by Vera's wild tale about the three men getting sucked into a bog and her aunt expecting them to return to life after being dead for three years.
One of Saki's best-loved stories, "The Open Window" exemplifies what one critic says is
that indolent, delightfully amusing world where nothing is ever solved, nothing altered, a world in short extremely like our own.
The narrative centers around a practical joke played upon the rattled Framton Nuttel, whose doctor has prescribed for him a "nerve cure" for which he is to go to the country and have "complete rest and an absence of mental excitement." Framton's sister has lived in the countryside, so she writes the letters of introduction for her brother which he can present to Mrs. Sappleton. Since she is not ready to greet Nuttel, Mrs. Sappleton sends her niece Vera to entertain Framton while he waits for her. However, the precocious niece entertains herself by playing the practical joke of making him believe that her uncle and Mrs. Stappleton's younger brothers and the dog disappeared when they went out on a hunt. When they do return, Framton is so horrified by the perceived "ghosts" that he gets up and runs.
To cure him after having a nervous break down.