Like most authors, I spend a lot of time and energy on the opening chapters. That’s where we hook the reader with a mix of plot, character, setting, and tone. The opening presents the greatest writing challenge. It’s also offers the most fun.

A lot of books founder after that sterling opening. For me, the trickiest part of a manuscript often comes when my protagonist, former CIA covert operative Phoenix Smith, starts gathering information and identifying suspects. She’s learning about the case, and research can slow the pace. If pages contain lots of dialogue and little action, the mystery reader slips off the hook.

Having struggled with this slowdown, I celebrated when Killer Nashville organizers assigned me to a panel on jumpstarting a stalled plot. The topic forced me to analyze how I deal with this common problem.

When I begin a book, I know—vaguely—how it’s going to begin and end. I anticipate a few specific events or encounters as milestones along the way. My dead zone falls in the early middle pages—say somewhere between 75 and 150—where Phoenix is running around tricking people into giving her information and figuring out what leads to follow. She hasn’t yet become an obvious threat to the villain, so the plot lacks the inevitable fast action of the last 50 to 75 pages. (Most of my manuscripts run 305 to 335 pages.)

Usually the storyteller’s sense of timing warns me to make something happen. A key sign that I need to pick up the pace is when a chapter ends without anything pushing the reader to say, “Well, just one more chapter.”

Years ago Janet Evanovich, author of the numbered Stephanie Plum series, told writers that when she didn’t know what would happen next, she blew up Stephanie’s car. That sudden, unexpected action became a running gag in her books.

The principle of surprising the reader holds true, but most of us can’t get by with blowing up more than one car. What I usually do is draw on one of three C’s: conflict, clues, and change. All three are constants in mysteries, of course, so I mean really big ones.

Conflict takes many forms, from a physical contest—a shootout, a car chase, a trap—to a psychological dilemma—opposing personal goals, ethical questions, gains vs. losses. Whatever the conflict, it has to grow out of that particular story and the specific characters.

Fortunately any book provides multiple sources of conflict: the villain, a witness, a suspect, the police, a loved one or friend or mentor or employer. And almost any protagonist experiences internal conflicts, but at some point the conflict has to become action, often when and in ways the reader isn’t expecting. In Show Me the Murder, Phoenix dreads attending a recital at the church, and encounters a hit-and-run.In Show Me the Deadly Deer, she responds to a call about a rabid deer and becomes a hunter’s target. In Show Me the Gold, she stops to check a camera left to catch vandals in a rural graveyard and disrupts the killer’s plans.

I work hard to conceal small clues, but one jumpstarter is revealing a major piece of evidence—a license plate, a weapon, a cell phone trace, a fingerprint, an alibi—that turns the story in a new direction.

In the manuscript I just finished, Show Me the Ashes, Phoenix deals with a cold case. She can’t find new evidence. The turning point comes when she realizes what’s missing.

Often Phoenix discovers a clue that contradicts an accepted fact or casts a different light on the connections between seemingly unrelated characters.

One big lesson I’ve learned: Don’t waste characters. If I give a character a name, you can bet that person will provide a clue, often disguised in humor and seemingly irrelevant at the time.

If all else fails, make a change. The most obvious ones are point of view (switching to another person) or time (a flashback or old letter). Thriller writers like those techniques, but I rarely use them.

I prefer switching from one narrative line to another. In Gold, that means going from the main plot of the aftermath of a bank robbery to a subplot, suspected elder abuse or pressure on Phoenix to get together with an admirer.

In Show Me the Ashes, I alternate two story lines, an imprisoned young mother’s (possibly) false confession and a series of increasingly bold burglaries.

Sometimes introducing a new setting or a new person to reveal a surprising twist moves the plot forward. I also like to change the tone occasionally. That usually involves a light scene in which my main characters either spar or work together in an unpredictable way.

No one thing works all the time.

—Carolyn Mulford