The dark side of crime fiction: why cults make the perfect thriller plot

When I told someone I know that the third book in my Dr Vanessa Marwood forensic crime series would focus on cults, they told me: I’d never join a cult. I'm too strong.

I get it. It’s comforting to believe we’d spot the danger, walk away, stay in control.

But cults don’t just lure the weak. They attract the lost, the idealistic, the ones searching for meaning. And that’s exactly why they’ve fascinated me, not just as a person, but as a writer of psychological thrillers. In (what I hope you'll think is) this twisty forensic mystery, forensic entomologist Dr Vanessa Marwood investigates a disturbing case where victims aren’t just murdered, they’re cocooned in silk. As Vanessa investigates, it becomes clear this isn’t a one-off crime. It’s part of something much bigger. A cult with beliefs that stretch far beyond life and death.

So why are we so fascinated by cults?

Because they’re real.

Real-life cults and true crime stories are often more disturbing than fiction: Jonestown, NXIVM, The Family, The Order of the Solar Temple. Even without mass tragedy, cults leave ruin in their wake, tearing apart relationships, warping identities and taking control in ways that can be hard to escape.

That’s what makes cults such a powerful force in psychological suspense and crime fiction.

• The loss of control: The idea that you could be manipulated without realising it.

• The people who aren’t what they seem: The neighbour, the teacher, the friend—hiding something dangerous.

• The price of belonging: Sometimes, the true threat isn’t the leader. It’s the followers willing to do anything to prove their loyalty.
  

Whether it’s a psychological thriller or a forensic mystery, cults bring paranoia, tension and a slow-burning dread that keeps readers turning the pages.

Why cult thrillers are getting darker

Cults in crime fiction aren’t just about eerie rituals and sinister leaders anymore. They’ve evolved into something more psychological, more insidious. Some trends shaping today’s cult thrillers include:

• More forensic-led investigations – Less blind faith, more hard evidence.

• Thrillers where the cult isn’t just in the past – Survivors who are still tangled in its influence.

• Cults that feel terrifyingly real – Less about robes and chants, more about manipulation, coercion, and control.

Readers want more than shock value. They want to understand how and why cults work, and what it takes to escape. That's what makes today’s cult thrillers are darker, sharper and more grounded in reality—perfect for fans of Gillian Flynn, Lisa Jewell and Val McDermid. The best thrillers about cults

If you're searching for the best cult thrillers or psychological thrillers about dangerous groups and hidden agendas, here are some unmissable reads.

The Girls by Emma Cline – A coming-of-age novel inspired by the Manson Family murders. If you want to understand how people get drawn into cults, this is a must-read.

Mo Hayder’s Ritual – A forensic thriller with disturbing cult-like rituals and a detective who gets far too close to the darkness.

Sharp Objects by Gillian Flynn – Not a cult thriller in the traditional sense, but a chilling exploration of power, control and twisted beliefs.

Of course I'd also recommend my novel Moth to the Flames for your next read, too! And if you're after a dark and gripping psychological thriller with a forensic twist, Moth to the Flames could be your next unputdownable read.

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And if you love talking crime fiction, cult thrillers, and forensic investigations, let’s chat in the comments—what’s the best cult thriller you’ve ever read?