A seraglio is a sultan's harem. The word is derived from the Latin serare which means: to lock up, to secure. For the narrator and his wife, Englishmen on vacation in Istanbul, the word's entomology takes on special significance. "Seraglio" is a tale of personal space and privacy in relationships and the narrator's marriage is in trouble as a result of his failure to understand the amount of space his wife requires.
Themes common to many of Swift's writing appear in "Seraglio." The narrator asks the question, "I wonder whether if a person does not know something has happened it is the same as if nothing had happened," (p.118) a philosophy of knowledge that first appears in "Hoffmeier's Antelope." He says this in relation to an affair that he had behind his wife's back. The problem in the short story is that his wife feels that she has been "violated" by one of the hotel workers, and the narrator is unsure whether or not he should believe her. If she had not told him, would he have ever considered the "attack" as a possibility? Probably not.
The main goal of this story seems to be an exploration of the husband and wife relationship. The exotic setting and dark events that surround this family drama are details required for mood only. This represents an interesting characteristic of Swift's writing, which is its darkness. Rarely are his characters happy, and when they are they seem to be uncomfortable with the feeling.