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How to write a compelling psychological thriller novel

When I first set out to write a psychological thriller, the first thing I did was look up “How to write a psychological thriller.” I came up with very little. It’s a complex genre that’s challenging to write, and there’s little information for aspiring thriller authors on how to create a compelling story that keeps readers guessing at every turn.

I just had to do it myself, based on what I’d gleaned from the books I’d read.

After finishing my psychological thriller, I learned a few things along the way, and so I thought I’d share them with you today in the hope that it helps you understand the genre better.

But what is a psychological thriller?

A psychological thriller is a story where the main character experiences a deep psychological conflict because of external circumstances, usually in a situation which creates paranoia and suspicion, which causes them to question their sanity. The protagonist must confront the very depths of their character in order to resolve the story, and it’s for this reason that psychological thrillers need to have strong character arcs. Characters often have unlikeable traits, but we root for them because of this suffering and potential for redemption.

(And the people around them usually turn out to be waaaay worse.)

Classic psychological thrillers include:

As you can see, the psychological thriller is a hugely successful genre when done right. They often straddle the line between horror and crime genres, but what separates a psychological thriller from horror is that it does not necessarily rely on explicit gore or brutality for its thrills. As the story progresses, it takes a harrowing situation and heightens the tension.

It’s psychological for a reason

It seems obvious, but it’s important to keep in mind that a psychological thriller is about the psychology of the main character. There is as much internal conflict as there is external conflict.

If there’s too much external conflict, it becomes a regular thriller.

If there’s too much internal conflict, it becomes a boring book.

As you’re writing, you need to allow space to express the character’s internal conflict, even if it’s in third person. It’s one reason a lot of psychological thrillers are written in the first person, to keep the tension close to the character, and thus the reader.

Your main character might have a documented mental health condition which makes them an unreliable narrator. It’s important to do significant research before writing about these very real psychological conditions to represent them accurately.

Or they could be an ordinary person in an extraordinary situation, whose mental state deteriorates as the story progresses. An excellent example in this latter category is the classic film Gaslight, from which the term gaslighting comes.

Start with familiar emotions

Contrary to popular belief (and the countless domestic thrillers out there) a psychological thriller does not have to start in a familiar place. It needs to start with familiar emotions. The reader needs to understand why the protagonist is in this situation and empathises with their psychological situation.

This is advice drawn from William Goldman’s classic book on writing Adventures in the Screen Trade. Feelings are universal, settings are not.

In Rebecca, the unnamed main character suffers from a lack of self-esteem when comparing herself to her lover’s former wife, Rebecca. Likewise, the terrifying paranoia of pregnancy and baby brain is experienced by many parents, which is why Rosemary’s Baby is so successful.

The biggest enemy is the self

Girl with split personality disorder showing two faces in two different moods

While many psychological thrillers will have antagonists, the biggest enemy the protagonist must conquer is themselves.

In The Silence of the Lambs, Clarice Starling must silence the screaming lambs from her childhood to save others, and herself. Hannibal Lecter is an antagonist in this sense, but he also enables her to understand her deep psychological conflict.

Think about what your main character must do to deal with their internal conflict. When you’re plotting the novel, make sure you include this as part of the story arc, and think about scenes that could reflect this progression.

Rely on the unreliable narrator

Everyone likes to present their best selves, and so do your characters.

But what if your characters are not as good as they appear at first glance? In a lot of psychological thrillers, the main character appears ‘normal’ at first glance. The reader can associate with them. But as the story progresses, they’re revealed to be more and more unhinged.

If you decide to go down this route, you must research the psychological condition your characters have – such as sociopathy – and understand the character traits associated with these psychological conditions. Drop hints as to these behaviours through the book so that when the truth is revealed, readers are shocked but not surprised, as they go back and piece it all together.

Everyone has secrets, including the author

Nothing is ever as it seems on the surface in a psychological thriller. What might seem like a normal loving family is gradually broken down through the progression of the story, as in Gillian Flynn’s Sharp Objects.

As the author, you know the secrets of your characters. But it’s not just the main character who keeps secrets from the reader. Each significant character should have secrets of their own that are revealed over the progress of the novel. This means you can keep the reader on their toes as they wonder what is really going on.

Walk the tightrope

With Rosemary’s Baby, Ira Levin keeps the reader guessing until the end by maintaining the thin line between ‘Is it supernatural forces or is it baby brain?’. Likewise, Gone Girl (inspired by Rosemary’s Baby), maintains the question ‘Did Nick Dunne kill his wife or did she disappear?’

Part of having successful plot twists and keeping the reader guessing is maintaining a novel that could go either way. Start with the question you’d like to maintain – when writing my psychological thriller, I wanted to walk the line of ‘Is something supernatural happening or is the protagonist going mad from the pressure of college?’

As you write, make sure the scenes reflect both sides of this question, and that the supporting characters express different perspectives on this issue – some could be convinced of supernatural influences, some could be convinced the character is going mad. Keep in mind that each supporting character has their own motivations behind what they say. Making the protagonist think they’re going mad could be part of their plan…

Drip feed information to your reader

One of the hardest parts of writing a psychological thriller is knowing just how much information to share at any time. It’s important to keep dishing out new information in nearly every chapter, but the main character must react to this information and process it internally. Err on the side of explaining too little than explaining too much.

Plan your reversals

Attractive cheerful young caucasian man watching horror movie in cinema theater.

While most information will be drip fed to the reader, you need to allow for moments of absolute bombshells – those reversals where the reader will be shocked by the turn of events.

Reversals are hard to write well. If you don’t set them up properly, the reader could outright reject your book for the preposterous twist. Do it well though, and you’ll have readers talking for years.

At least one of these reversals should take place at the end of the book – who can forget the ending of Rosemary’s Baby?

The key to writing a reversal is to have the twist in mind from the very start and plan backwards. While some successful thriller authors make up the story as they go along, it’s incredibly difficult to build in twists and turns without a basic plot outline. Think about how you want your reader to perceive your protagonist and novel until the plot twist, then structure it appropriately.

Revelations must be earned

Psychological thrillers often involve informal investigators, such as family members uncovering a secret, journalists investigating a mystery, or holidaymakers who have inadvertently witnessed a crime. While they will have their own ways of uncovering the secrets through the story, much like the more formal crime procedurals, revelations need to be earned. The characters can’t just turn up and have everything revealed. They need to work for the information.

If you’re trying to persuade people to give up long held secrets, then there needs to be a reason they finally talk. Ask yourself, why now? Has the investigator uncovered a new piece of evidence or clue which forces the secret out? Is the investigator incredibly persuasive? Does an event bring back memories of a time that had been forgotten (or ignored) from town history? All these could be prompts for how to reveal the mystery.

How to end a psychological thriller

There are three main endings to psychological thrillers. Usually the ending should be deliciously satisfying or leave the reader shell shocked (or both if you’re really good).

Bittersweet satisfaction

The protagonist may accept their situation and make the best of it, as with several of the books I’ve listed. Or the protagonist deals with their psychological challenges and faces their demons. But psychological thrillers don’t have happy endings; they’re bittersweet. The main character has been broken and put back together by the end of the novel – they’ll never be the same.

The revelation of true self

Alternatively, the character who starts with an appearance of sanity has revealed their true self to the reader. And while this could be a violent psychopath, there’s also a satisfaction in them getting away with it. Alternatively, the protagonist could be a victim of the person who reveals their true self.

Some examples include:

Losing sanity

This is where the main character has completely lost their sanity. This is a difficult ending to resolve satisfactorily, because it relies on convincing the reader of the psychological reality of the character’s descent into madness.

An example of this is:

  • The Yellow Wallpaper by Charlotte Perkins Gilman

Conclusion

When executed well, the psychological thriller is one of the most exciting, page-turning genres. I hope these tips have helped you understand what makes a great psychological thriller. Remember, if you have questions, ask away in the comments section below.