Mr. Nuttel visits Mrs. Sappleton because of his exhausted nerves. During the late 1800s, a long recuperative stay in the country was considered a great restorative for one's mental health. Nuttel's sister writes him several letters of introduction and it is through one of these letters that he meets Mrs. Sappleton at her quiet estate. Mr. Nuttel hopes that some time at Mrs. Sappleton's house will restore his nerves so that he can return to his regular life.
In the story "The Open Window" by Saki, the reader is not sure about the exact nature of Nuttel's nervous state or how he got to be this way. Through indirect characterization, Saki explains to the reader that Mr. Nuttel is quite nervous, and this helps to create the rest of the story and Mr. Nuttel's eventual scare at the hands of a mischievous young girl.