Framton Nuttel, the protagonist of Saki's "The Open Window," goes to visit Mrs. Sappleton upon the advice of a doctor and his sister. Frampton has been diagnosed with a nerve problem and has been advised to go out on a trip visiting complete strangers as a "nerve cure" for his illness.
Essentially, Frampton is a nervous man. A trip is "what the doctor ordered." Upon the advice of his sister, who had previously visited Mrs. Sappleton, Framton includes her home as one of the formal visits he takes in order to both rest and keep himself from seclusion.
Although the trip is meant to calm his nerves, it does everything but do just that. In "reality," Frampton leaves the Sappleton home more nervous than he was when he arrived.