I talk to a lot of writers, and I often get the impression that the act of writing a synopsis is among the most hated of the many tasks required of a working writer. As an agent, I can assure you that, yes, this is something you have to do. I always ask for a synopsis when I request a novel manuscript, and I know few agents who don’t. This becomes even more important as you find repeated success as an author. Then you start having the option to sell new work on proposal, and you simply can’t do so without a bulletproof synopsis.
This doesn’t have to be a daunting thing. Yes, it is a different kind of writing, but at the core, it’s all stuff you know better than anyone else on the planet. These are your characters. This is your story. Telling us about the novel will come quicker and easier than writing the novel, and if it doesn’t, that’s likely an indication that you should be revising instead of worrying about a synopsis.
I’ll break it down a bit and offer some tips.
A synopsis is a description of what happens in your narrative from start to finish. Include moments of action that drive the tension upward and move the plot forward. Hit all of the major plot points and connect those dots in a concise, linear, and informative manner.
Give us the entire storyline. Yes, spoil the ending. That’s the point. We want to see what happens, that the story arc is complete, that the resolution works with the buildup, etc. You can give us a cliffhanger in your pitch, but in a synopsis, you can’t be coy.
Include the major players as they become pertinent. Don’t delve into an in-depth character study (or a bulleted list, for that matter), but make sure we know the characters’ desires and why they are doing what they’re doing. This can be as simple and brief as a single clause or even a single word which should significantly nudge the character off their equilibrium, contributing to the motion of the plot.
Maintain a forward motion in your synopsis. Don’t stop to focus on any one event for too long. Just tell us what happens, keep the description to a minimum, and then move on to the next thing. Avoid pasting in narrative or dialogue from your manuscript. Your manuscript and synopsis have different functions and should not read similarly. By comparison, your manuscript will appear bloated and lacking focus, while your synopsis will appear terse and lacking voice. In reality, though, they’re both accomplishing exactly what they’re meant to.
A common misconception is that a synopsis is the second paragraph (or “book” paragraph) of your query. That is not true, but there is some good information in there that could help you. In your query, you’re presenting the compounding of tension. That shows, on a very basic level, the core functionality of acts one and two. That information, should find its way into your synopsis, greatly expanded and continued. Remember, a synopsis presents the complete story arc, and you can’t have a complete story arc without events that compound tension and ultimately propel the plot.
Regarding length, be prepared to get your information across in anywhere from one to five double-spaced pages. I personally prefer two to three, which is much more common in my experience, but I’ve seen situations that demand otherwise. Still, that should be more than enough room to tell me on a basic level what happens in your manuscript. To quote Oliver de la Paz, “What is your book about in a page? Now tell me what your book is about in two sentences. One sentence. A word. A look.” This is the level of knowledge you should have of your work before you query, and it’s what you convey in a good synopsis. If you can’t express what happens in your manuscript in one double-spaced page, you either have some revising to do, or you’re too close to your work and need to enlist the help of a writing partner, editor, or critique group.
Basically, the goal of a synopsis is to be functional. It doesn’t have to be pretty. We’ll get your voice from the manuscript, so focus on keeping your synopsis lean. Everything you include should have a strong function, if not two or three simultaneously. That is important. If you meander and flounder about in your synopsis, it doesn’t speak well of you as a writer with a strong grip on the economy of language. Remember, everything you do in your attempt to get published – your query, synopsis, manuscript, presence – is an audition. It’s an argument that you have what it takes to be a professional writer. Consider this just another opportunity to show me that you can perform on a professional level.
Examples of good synopses can be found here: http://www.writersdigest.com/editor-blogs/guide-to-literary-agents/synopsis-writing