The writing of Show Me the Ashes, the fourth book in my mystery series, has been going slowly.

Opening chapters always take me roughly a third longer than the middle ones and twice as long as the last ones. In the beginning, I’m creating new characters and settings, struggling to drop in essential backstory for new readers without boring old ones or slowing the narrative, and revealing just enough about the crime that will be solved in the next-to-last chapter.

Rewriting Chapter 6 a week ago, I realized I had to shift gears. I had been working from a one-page plot outline that covered mostly the beginning and the end, a list of characters, and general research on the plausibility of my plot. With Phoenix leaving the familiar streets of Laycock to study the key crime scene, I had to get down to the nitty-gritty.

To do that, I spent

• two days researching arson and applying that to the crime scene,
• half a day writing a timeline tracing suspects’ movements that night,
• half a day visualizing and sketching the crime scene and the small town where Phoenix investigates.

Then I rewrote Chapter 6 and started thinking ahead. Time to go to the next phase, to figure out the pacing of the book—not just what happens but when. I do that by outlining scene by scene, chapter by chapter. Yesterday I outlined the first six chapters, all well beyond first draft but not polished, and then the next 18 unwritten chapters. That outline will change regularly, guiding yet allowing surprises.

My books run 32 to 36 chapters. By the time I write Chapter 24, l expect to know what happens in the final chapters.

Tomorrow I begin writing Chapter 7.

—Carolyn Mulford