I should be a professional book photographer.

What makes a story compelling? Which is to say, what makes us as readers want to keep reading? Is it lyrical prose? Mystery? Suspense? Character? Conflict? Some combination of some or all?

I recently read The Starless Sea by Erin Morgenstern with a book club at work, and the reactions to the novel were split. About half of the group loved it for its world-building, beautiful prose, and deep themes. The other half of the group (of which I fell into), agreed the book had all of those things but were also frustrated at the slow pace, passive protagonist, and repetitious plot.

This got me thinking about what different kinds of readers value. In this case, half of our group really valued world-building over everything else, while the other half was interested in character and plot over everything else.

What fell flat for me was what I’ll call narrative propulsion. I think narrative propulsion can be achieved in any of the ways listed above, but I also think that each of those ways has a limited energy. Sort of like a spaceship punching out of Earth’s gravity well and making a break toward the stars, a book needs to use multiple forms of fuel to keep a reader engaged–especially when your book is just shy of 600 pages.

The Starless Sea handles narrative propulsion masterfully for the first third of the book. The writing is gorgeous, the themes interesting, and the mystery at the heart of the story intriguing. But as the story goes along it relies on that same fuel to push the story along instead of introducing new types.

The other side of narrative propulsion that’s somewhat unique to The Starless Sea is its structure. We’re used to following one or a few characters that may each have their own storylines, but are each in service of a single overarching narrative. The Starless Sea alternates between the main plot, that of Zachary Ezra Rawlins, and a series of vignettes pulled from the books that Zachary’s story revolves around. While this adds a lot of variety to the book, it also breaks the narrative into chunks and adds complexity to an already dense read. In short, it interrupts any narrative propulsion built from chapter to chapter. I read the book pretty quickly, spending time with it everyday, and because of the vignettes between the main chapters I often found myself having difficulty remembering what had just happened in Zachary’s storyline.

In short, I think it’s dangerous for authors to rely on just a few aspects of storytelling to hold a reader’s attention. A story needs to constantly build on itself, adding new depth to its plot, characters, world, and theme, otherwise there is a risk that a reader will become bored and leave, no matter how beautiful the writing.