Narrative hook

A narrative hook (or just hook) is a literary technique in the opening of a story that "hooks" the reader's attention so that he or she will keep on reading. The "opening" may consist of several paragraphs for a short story, or several pages for a novel, but ideally it is the opening sentence.

One of the most common forms is dramatic action, which engages the reader into wondering what the consequences of the action will be. This particular form has been recommended from the earliest days, stemming from Aristotle.

The use of action as the hook, and the advice to so use it, is so widespread as to sometimes lead to the use of the term to mean an action opening, but other things can be used for narrative hooks, such mysterious settings, or engaging characters, or even a thematic statement, as with Jane Austen's opening line, "It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife." (Pride and Prejudice)

When a story does not lend itself to a good hook when it is laid out linearly, the writer may tell the story out of order to engage the reader's interest. The story may begin with a dramatic moment and, once the reader is curious, flashback to the history necessary to understand it. Or it may be told as a story-within-a-story, with the narrator in the frame story telling the story to answer the curiosity of his listeners, or by warning them that the story began in an ordinary seeming way, but they must follow it to understand latter actions. A famous early example of this technique was used in the One Thousand and One Nights, also known as the Arabian Nights, in which the frame story consists of Sheherazade telling stories to King Shahriyar; she must keep him 'hooked' to each of the stories, in order to prevent him from executing her the next morning.

In medias res is where the relating of a story begins at the midpoint, rather than at the beginning. This form of story telling might be used as a narrative hook. Narrative hooks often play an important role in suspense thrillers and mystery fiction. An example of both these occurrences is One Thousand and One Nights, in which a tale, "The Three Apples," begins with the discovery of a young woman's dead body, thus keeping the reader interested in "whodunit."

...
Wikipedia