Agatha Christie was the real-life Gone Girl of the 1920s.

Agatha Christie is the most popular mystery writer of all time. This week, a new movie version of her classic Murder On The Orient Express is opening in cinemas.

But the most fascinating of all the Agatha Christie mysteries is the mystery of her disappearance, which gripped the world for 11 days almost a century ago.

It was just after 9.30pm on Friday, December 3, 1926, when Christie got up out of her armchair at her home in Berkshire. She went upstairs and kissed her sleeping seven-year-old daughter, Rosalind. Then she got into her car and drove off.

The next morning, her car was found abandoned, with the bonnet up, on a steep slope, near a natural spring known as the Silent Pool. Inside was a fur coat, a bag of clothes and an expired driver’s licence.

Christie was already a popular author, with her sixth book – The Murder Of Roger Ackroyd – recently published. The disappearance of the “Lady Novelist” made front-page news, in the UK as well as the US, and led to one of the biggest missing-person searches ever.  

Three police forces competed to find her, sending a total of 1000 officers out to comb the countryside. On top of that, 15,000 volunteers joined in. Bloodhounds sniffed the ground, and biplanes flew low in the sky. Lakes were dredged.

Two other popular mystery writers, Sir Arthur Conan Doyle and Dorothy L. Sayers, were brought in to help out.  

“A mother’s love for her child is like nothing else in the world. It knows no law, no pity. It dares all things and crushes down remorselessly all that stands in its path.” – Agatha Christie (photo of Agatha Christie with her daughter Rosalind). #agathachristie #mothersday #love #daughter #author #quote

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Doyle consulted a famous psychic, Horace Leaf, giving him one of Christie’s gloves. Leaf claimed the person who owned the glove was still alive, “half dazed and half purposeful”.

Meanwhile, Sayers visited the place where Christie’s car had been abandoned and declared it was “a voluntary disappearance”.

Speculation was rife. Had Christie committed suicide? Was it all a publicity stunt? Or had she perhaps been murdered by her husband Archie, a dashing WWI fighter pilot?

Although it wasn’t public knowledge, Christie’s marriage was on the rocks. Her husband was having an affair with a younger woman, Nancy Neele, and wanted a divorce. On the Friday that Christie disappeared, her husband had gone off to have a weekend with his mistress.

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In the eyes of the police, Colonel Archie Christie was a prime suspect in his wife’s murder.

But 11 days after her mysterious disappearance, Christie was found. Bob Tappin, a banjo player at the Swan Hydro hotel in Harrogate, recognised the woman dancing the Charleston to “Yes, We Have No Bananas” from photos in the newspaper.

Christie had checked in to the hotel under the name of Teresa Neele – the same surname as her husband’s mistress – and claimed she was visiting from Cape Town.

She had even put an advertisement in The Times, reading: “Friends and relatives of Teresa Neele, late of South Africa, please communicate.”

Tappin called the police, who notified Christie’s husband. He turned up to the hotel, but Christie made him wait while she changed her clothes.

The official explanation put out at the time was that Christie had suffered memory loss, but not everyone believed it.  Politicians demanded that compensation should be paid for the cost of the search.

PODCAST: Mystery overload, Clare and Laura talk about the Netflix mystery documentary The Keepers.

Christie only ever made one statement about the disappearance in her lifetime: “For 24 hours I wandered in a dream and then found myself in Harrogate as a well-contented and perfectly happy woman who believed she had just come from South Africa.”

But what really happened to Christie? Numerous books have been written, trying to solve the mystery of her disappearance.

In Agatha And the Missing Eleven Days, Jared Cade claims it was all planned. He says Christie was just trying to disrupt her husband’s weekend with his mistress and “make him suffer”.

In The Finished Portrait, Andrew Norman argues Christie was in a “fugue” state – out-of-body amnesia brought on by stress.

Agatha Christie, the undisputed Queen of Crime. #AgathaChristie #Books #Bookstagram #Author #DetectiveFiction #icon

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Meanwhile, Andrew Wilson, author of the novel A Talent For Murder, believes Christie set out to commit suicide, crashed her car, then felt so guilty that she pretended to have lost her memory.

In the past few years, the similarities between Christie’s life and Gillian Flynn’s novel Gone Girl have got people talking. Writer Catherine Ostler has dubbed Christie “the original Gone Girl”, claiming that Nick and Amy Dunne “are a latter-day Archie and Agatha”.

Whatever the truth behind Christie’s disappearance, it did nothing to help her marriage. The couple divorced soon afterwards, and Archie Christie married Nancy Neele. Agatha Christie went on to marry a much younger man, geologist Max Mallowan, and to continue to write best-sellers.