The Vanishing of the Tromp Family

It started as an ordinary day in Silvan, Victoria, a quiet, rural town in Australia. The Tromp family Mark and Jacoba, along with their three adult children, Riana, Mitchell, and Ella—were well-liked, hardworking farmers who ran a successful berry business.

By all accounts, they were normal.

Then, they vanished.

The Sudden Escape

On August 29, 2016, the Tromps abandoned their home without warning. They piled into their silver Peugeot and fled, leaving behind:

✔ Their phones

✔ Their passports

✔ Their credit cards

They cut off all ties to the outside world.

Nobody knew why.

In the days leading up to their disappearance, Mark had become increasingly paranoid, convinced someone was watching them and their lives were in danger. He claimed their phones were being tracked, their money wasn’t safe, and the only way to protect the family was to disappear.

And so, the Tromp family ran no luggage, no clear plan, just an overwhelming sense of fear.

When Victorian Police arrived at the Tromp family‘s home in Silvan, Victoria, on August 30, 2016, they found the doors unlocked. A station wagon was missing, but other cars had been left behind. The keys still in the ignitions.

Passports, mobile phones and bank cards belonging to the family of five were discovered inside, along with piles and piles of financial and business documents. They were neat and ordered, almost as if someone had been searching for something, police told The Daily Telegraph.

By then, the Tromps, Mark, 51, his wife Jacoba, 53, and their three adult children, Riana, 29, Mitchell, 25, and Ella, 22 were already hundreds of kilometres into a journey that would spark one of the most bizarre missing persons cases in recent Australian history.

A Journey into Madness

They drove more than 1,000 miles, heading north through New South Wales and beyond.

Then, things got strange.

Somewhere along the way, Mitchell, the eldest son, had enough. He didn't believe his father’s paranoia. In secret, he slipped away and took a train back home.

The rest of the family pressed on

But the fear kept growing, almost like a virus spreading among them.

Riana and Ella began feeling the suffocating paranoia too.

They started questioning their father’s grip on reality.

The fear had become too much.

Eventually, they also fled.

Ella stole a car and drove home alone.

Riana wasn’t so lucky. Police found her in a catatonic state, unable to speak, as if trapped inside her own mind.

Now, only Mark and Jacoba remained.

The Parents Unravel

The couple kept driving further into the wilderness, deeper into delusion.

Then, Mark did the unthinkable.

He abandoned Jacoba and disappeared into the bushland.

When police found him days later, he was disoriented, confused and completely alone.

Jacoba, also in severe distress, was eventually hospitalized.

The Aftermath

One by one, the Tromps returned home but none of them could explain what happened.

Mark later apologized for what he called a "family breakdown," but never revealed what triggered it.

Psychologists suspected "folie à plusieurs," a rare case of shared delusion, where paranoia spreads like an infection.

Fun Fact: "Folie à Plusieurs"

("foh-lee ah plu-zee-air")"

"Folie à plusieurs" is a French phrase that translates to "madness of many" and refers to a psychiatric condition where multiple individuals share the same delusional beliefs or symptoms, essentially meaning a shared psychosis affecting more than two people; it's a variation of "folie à deux" which refers to shared delusions between only two individuals.

✔ There was no real stalker.

✔ No government conspiracy.

✔ No financial problems.

So, why did they run?

The Tromp family has never spoken publicly about their week of madness.

Their bizarre disappearance remains one of Australia’s strangest unsolved mysteries.

What really happened?

Was it a mental breakdown? A cult-like belief? Or something darker?

Some questions may never be answered.