A narrative essay is a story. Usually it's a personal anecdote or experiential piece, and it follows the same pattern as all fiction. Its three elements or "parts" are exposition, or background information, followed by complication, the events of the narrative, and resolution, the story's end. A narrative essay may be a story or it may be about a story, as in a book summary; both essays will still contain these three elements.
Exposition is the background information necessary for a reader to understand the story. In a narrative essay, the exposition can be presented in two ways. If the essay is a story itself, the exposition in the opening paragraphs reveals setting and situation through dialogue, a character's thoughts or words, documents such as letters -- epistolary tales are a fascinating narrative form -- or through the author's narration. If the essay is informing readers about a story, the exposition presents the essay's thesis about the story in an opening paragraph.
Complication is the story itself, which stays the same whether the essay is a story or a piece about a story. This part of the essay develops the narrative by introducing conflict. Conflict creates a protagonist and antagonist, a series of events and a story arc leading to an ending, all of which make up the narrative. In an essay about a story, complication still tells the gist of the story, and the writer adds explanations or commentary.
The resolution is the story's ending. It concludes the narrative essay if the piece is a personal or fictional anecdote; if the essay is discussing an already-written narrative, then the essay should follow the story's resolution with discussion or comments about the story. For example, a narrative essay that is a personal story might end, "That's how my father taught me always to bring my toolbox, even if I only need one tool," an ending that reveals the essay's point. In a summary essay, there is commentary: "Hamlet's death ends the play, but not the controversy over his last words."
Sample Essay Ideas
A narrative essay that is also an expository summary of Herman Melville's "Moby-Dick" summarizes plot points and comments on them. The exposition of that essay explores Melville's themes; the complication presents the plot. The essay's resolution gives way to comments on specific points. If, however, the instructor's assignment is to write a narrative essay about a personal experience that was a voyage of discovery such as Melville's, then exposition, complication and resolution make up the story itself.