There is no substitute for a solid understanding of the work you are writing about. A good knowledge of the plot lines, development and resolution of the story will allow you to write more fluidly and efficiently. Check back through the book and remind yourself what you found most interesting, exciting or thought-provoking when you first read it. Use these parts of the narrative as key events in your plot summary.
Authors use repetition to emphasise aspects of their story. Look for patterns of events, imagery or character traits that are meaningful and support the author's message. These patterns frame the plot and provide clues as to how the story will unfold. Use them in your essay to illustrate how the plot is built on a structure of recurrent layers of meaning. Explain how narrative events gradually reveal the protagonist's character and intentions.
Often, the most interesting aspect of a book lies in the problems it poses to the reader. Unexpected plot developments, unresolved storylines and rhetorical questions posed by the author provide elements for consideration in a plot summary. Show your reader how missing evidence, uncharacteristic behavior or a volte-face affects the pace and direction of the plot. The author's reason for including a problem in a narrative is usually to highlight another more important aspect of the plot.
A good summary uses quotations from the book simply as illustrations rather than as tools for analysis. They provide support for your ideas and help the reader understand how the author writes. Use quotations that show how the narrative elements of the plot are connected and how they conform to the genre the author has chosen. Show how the plot both contributes to this genre and is driven by it in order to reach its resolution.