People at book signings often wonder if there’s some trick or secret technique for writing a mystery. They ask about plot, as if that were the key. The plot is an engine, but engineering the spark plugs is the more significant task. Spark plugs ignite the mixture of fuel and air causing a small explosion which creates hot gas. The gas pushes the piston down. And what is this small critical component of the plot that powers the novel’s crankshaft, keeps the pistons pumping and moves the big vehicle forward?
I call it the “Decepticon.”
I know all about the other Decepticons – the shape-shifting machines in the Transformers movies. Mine are more humble, but in their own way just as powerful, and just as hard to find. In a mystery novel a Decepticon can be a clue, but never an obvious one. Its function is to deceive; to mislead the reader by hiding its true identity in plain sight. When the detective feels something askew about the case he or she is investigating, when the facts don’t add up, when they return to the depositions and the “murder book” one more time, they’re searching for the Decepticon, the fact with two faces, the apparently mundane detail freighted with significance.
Seeing things that others don’t
Decepticons, when decrypted, allow the great epiphanies of logical deduction, and the solution of the crime. The best ones have been laid out for us from the beginning, which makes perfect sense; who is the detective after all, but the person who sees things that others don’t and understands the connections between them that other people miss?
At the beginning of the great mystery film Charade, Audrey Hepburn plays Regina Lampert, whose enigmatic husband has been killed and thrown off a train. All their belongings, including the furnishings of their Paris apartment, have been liquidated, but where is the money? Inspector Grandpierre of the French police calls her into his office and says … Well, here is the scene from the shooting script:
These few things are all that was found in the
train compartment. There was no other baggage.
Your husband must have been in a great hurry.
He begins to take them out, placing them on the desk,
identifying each item as he does.
One wallet containing four thousand francs — one agenda — (pausing, he opens the notebook) —
his last notation was made yesterday — Thursday — (reading) “Five p.m. — Jardin des Champs-Elysees” (looking up) Why there?
I don’t know. Perhaps he met somebody.
Obviously. (returning to the items in the basket) One ticket of passage to South America — one letter, stamped but unsealed, addressed to you —
REGGIE (lighting up)
A letter? May I see it?
GRANDPIERRE hands her the letter and watches her closely as she reads it.
“My dear Regina: I hope you are enjoying your holiday. Megeve can be so lovely this time of year. The days pass very slowly and I hope to see you soon. As always, Charles. P.S. Your dentist called yesterday. Your appointment has been changed.” (She looks up, puzzled) Not very much, is it?
We took the liberty of calling your dentist — we thought, perhaps, we would learn something.
Yes. Your appointment has been changed. (he smiles at his little joke, then returns to the basket). One key to your apartment — one comb –one fountain pen — one toothbrush — one tin of tooth powder (he looks up) — that is all.
I quote the full scene because it represents one of the greatest single acts of misdirection and one of the finest Decepticons ever put on film.
If you haven’t seen this delightful film stop reading, go and watch it now It’s available on many streaming platforms or you can rent the DVD from your local library.
Of course the money was right in front of us all, in the stamps on the envelope, precious rarities worth hundreds of thousands of dollars. The verbal sleight-of-hand in the reveal teaches you as much as any creative writing course. Grandpierre says: “A letter, stamped but unsealed, addressed to you.” This sentence puts the stamps on exactly equal footing with the physical state of the envelope itself and immediately shifts attention to the contents of the letter. By the time the policeman has made his little joke about the dentist, the stamps are long forgotten.
Until the big reveal at the end of the movie.
A Good mystery writer is always on the lookout for them
There are two types of Decepticons, the Found and the Bespoke. The Bespoke is like a tailored suit, designed for the occasion, a clue of convenience, if you will. They always feel slightly contrived, because they are. You sit down and contrive them because you need a red herring or a false lead at a certain moment in the story.
It’s the Found Decepticons that give mysteries their mysterious life force, and a good mystery writer is always on the lookout for them. They feel fresh because they force you to bend the plot around them; in a sense they recreate the plot, or at least move it in new directions. You can imagine Peter Stone, who wrote the Charade screenplay, wandering through the Thursday afternoon Rond Point stamp market in Paris, and realizing with a thunderclap of perception, how a valuable stamp could conceal a fortune and rewire a thriller’s storyline.
So that would be my advice to beginning mystery authors. Keep your eyes out for the small anomalies in your life, and use them when you find them, no matter how much you have to change your story to fit them in. Those changes keep your book’s engine roaring and your plot moving ahead. The spark plug is a humble little item, but you can’t drive without it.