How to Write Unputdownable Psychological Thrillers

“I read your pages,” said my critique partner. “And I think it’d really increase the tension if you tore the one page out of the book that your main character needs.”

It was a great suggestion. My main character was poring over hospital records, searching for a clue about her daughter’s disappearance. In my original draft, she discovered that the records for the day in question simply didn’t exist. But if that crucial page had been torn out instead, the stakes and tension would skyrocket.

I thought about it for a few days, and finally decided against making the change. Why?

Because adding tension for tension’s sake can backfire, creating a shallow narrative that doesn’t resonate with readers.

Avoiding the Trap of the “Plastic Novel”

We’ve all read them. Stories that don’t quite hold together. They feel lightweight, with no substance. The characters are paper-thin, and the plot is easily breakable.

In psychological thrillers, the last thing you want to do is write a “plastic novel”—a story that feels artificial, breakable, and lacking substance. This genre demands depth. Readers expect stories that dig into the human psyche, unearth dark secrets, and explore emotional turmoil. A plastic novel may hook readers temporarily, but it won’t keep them invested, leading to poor reviews, lower sales, or disinterest from publishers.

So how do you avoid this trap? By ensuring your thriller has depth, complexity, and, most importantly, substance.

The Pillars of a Suspenseful Thriller

To craft a thriller that not only has substance but also that unputdownable quality of bestsellers, several key elements are essential.

Let’s dive in.

Atmosphere

Weather has a lot of sway with readers in a suspenseful thriller. Why? Extreme conditions amplify tension. A lingering heatwave frays nerves, pushes characters to their breaking points, and creates an undercurrent of unease. Often, this oppressive heat will culminate in a climactic storm, breaking the tension alongside the story’s dramatic finale.

Incorporating weather into your story is like adding a character—one whose sole purpose is to amplify the conflict. Freezing temperatures add physical risk. Approaching storms introduce a ticking clock element, adding urgency. Heat breeds impatience and irritation. Even drought can symbolize a slow burn of desperation. Use weather to mirror and heighten the emotional stakes of your story.

Fast Pacing

While some suspense novels build slowly, creeping under your skin (thinking of you, Silence of the Lambs), most thrillers pick up speed quickly and never let go. Pacing in thrillers should never stall. A few ways to maintain a breakneck pace?

• Shorter chapters: This encourages readers to keep turning the pages.
• Staccato sentences:  Quick, punchy language mirrors the intensity of the unfolding action.
• Every scene drives the story forward: No wasted conversations or unnecessary exposition—every word should push the plot toward its climax.

High Personal Stakes

When I first started writing thrillers, the main conflict always ended in the threat of physical harm for my main character.

But in psychological thrillers, the danger is often more insidious. The true threat lies in the character’s mental and emotional state. While the body can heal, a fractured mind may not.

So, what vulnerabilities does your character have? What emotional wounds could the antagonist exploit to torture them on a deeper level? Target these areas and it will immediately increase the personal stakes for your character.

Secrets

In an earlier post, I covered in detail how to layer secrets into your suspense to increase tension, so here I’ll just cover it lightly.

Secrets are the lifeblood of suspense, particularly in the early stages of the story. Your first Act should be packed with them, creating intrigue and setting the stage for revelations later on. Act 2 gradually unravels these mysteries, offering tantalizing hints that keep the reader hooked. By the time you reach Act 3, the secrets should be exploding into the open, transforming the story and its characters.

Unreliable Characters

Trust no one in a psychological thriller. Assume that your characters, even your protagonist, are always lying or withholding the full truth. Readers of this genre expect deception, so take advantage of their mistrust. Who in your story is clearly untrustworthy? Who appears honest but has hidden layers? Play with these expectations to keep your audience guessing.

A Masked Antagonist, With A Relatable Agenda

One of my favorite parts of writing in this genre is creating an antagonist that is irredeemable yet relatable. The more human and understandable they are, the more chilling their actions become. To deepen the suspense, often the true identity of the antagonist remains a mystery until the middle or end of the story. In some cases, there are multiple suspects, and part of the challenge for the reader is to figure out the villain’s identity before the protagonist does.

Conclusion

An unputdownable psychological thriller needs more than just surface-level tension and twists. It requires depth, substance, and a careful balance of fast pacing, high stakes, and well-crafted characters. By focusing on atmosphere, secrets, unreliable characters, and a chilling yet sympathetic villain, you’ll create a story that truly is unputdownable.