The Day I Accidentally Committed to Writing Tahitian Vault

In my ninth thriller, Signal Code, I put a “coming next” blurb in the back of the book. It sounded great at the time:

“A forgotten grave on a remote motu. A missing submarine. Gold that shouldn’t exist in French Polynesia. And a volcanic mound deep in Bora Bora’s lagoon that’s not just rock. … Because what lies beneath the lagoon is more valuable than gold—something Imperial scientists buried when the war turned against them.”

The only problem was–

I had no idea what Imperial scientists had buried.

Now I had to invent it.

This is the core of writing a thriller–the mystery

It’s the foundation on which the entire story stands.

I call this the What, Why, and Who.

These are the reasons readers keep turning the pages.

Personal jeopardy, actions, and locations–the thriller part comes later.What is it? The object, the macguffin, or the consequences of someone’s actions.

Why is it important? If the protagonist doesn’t solve the problem (What), some bad consequence happens.

Who is involved? The protagonist and antagonist feel more real, and we invest more psychic energy worrying about some we feel we know and care about. Or that we hate and need to see defeated or put in their place.

I planted the seed in chapter six of Celtic Omen without thinking anything more than character diversion. As a quick reminder, Eyrun said to her AI assistant, “Look into potential projects in French Polynesia and give me three options.”

That’s it. Seed planted.

Was I thinking of a book? Only in the widest sense.

As I wrote Signal Code, the idea took root. No spoilers, but Signal Code mainly involves Darwin and Zac. Eyrun is largely absent. But she’s a core series character. So I used a side story–a trick to keep Eyrún in readers’ minds.

In chapter 12, while Darwin is in Vatican City and worrying about his role since the election of a pope, Eyrún mentions Bora Bora as one of several promising expeditions needing leadership. She said, “If you don’t want it, maybe I’ll go.”

This put Eyrun in the novel, “but offscreen.”

In chapter 29, Darwin is trapped, a regular occurrence for him, and pictures Eyrún in Bora Bora, “mini-umbrella drink in hand,” leading an ACA project.

The Tahitian Vault mystery was building in the background, but still a vague idea.

In chapter 50, Eyrún, now in Bora Bora, exchanges messages with Darwin. She says she got an “odd magnetic reading” below the reef and it’s “probably nothing.”

Now, Bora Bora had a mystery, and when Darwin and Eyrún meet again at the end of the book, she’s tan from her time in paradise, and they decide to go back.

That decision led directly to the Signal Code epilogue and the preview of Tahitian Vault that included gold, a wartime mystery, and something hidden beneath Bora Bora’s lagoon.

It was taking shape. I had parts of the What. Darwin and Eyrún were part of the Who. But I still had no Why. Uh-oh.

Readers often imagine authors working from a complete blueprint. Sometimes that’s true. But more often, at least for me, the process feels a lot like archaeology.

You don’t uncover a buried city all at once. First, you find a coin. Then a wall. Then a doorway. Eventually, you realize they’re all connected.

Bora Bora is a fabulous destination. Exotic and enviable.

The challenge was figuring out What was hidden beneath the lagoon and Why anyone would care enough to kill for it.

Readers often ask me how I come up with ideas for my novels. The next few Debriefs will do exactly this: give you a window into my process for coming up with an idea and building a thriller novel around it.

Next month in Debrief, I’ll tackle how I build out the What and figure out a Why. Along the way, I’ll talk about Who, because it’s characters who make a story worth reading.

After all, if I didn’t know what was buried beneath Bora Bora’s lagoon, how could Darwin? And, if I didn’t know why it mattered, why would Darwin risk his life to find it?

Until then,

Dave