Few people go on holiday with murder on their mind.
However, that's exactly what an Egyptian river ship has accused a famous guest of plotting when she sailed with them in 1933.
Fortunately that guest was Agatha Christie and the murder she was devising was the plot of her Hercule Poirot novel Death on the Nile.
The SS Sudan is a storied paddle boat from the 1920s which claims to be the "most beautiful boat cruising down the Nile".
Today the suite in which Christie and husband stayed is now named in her honour, and can be hired out for $7,925.
"It was on board this historic vessel in 1933, when she was accompanying her husband on an archaeological mission, that the queen of suspense found the inspiration for Death on the Nile."
In the book the SS Karnak - a thinly guised Sudan - is the setting for a honeymoon trip cut short by murder.
It's a bit of history that the ship has been living on for the past 90 years. In 2004 the SS Sudan was even the filming location for a TV adaptation of the book and it regularly hosts guests on an eight-night Death on the Nile cruise.
However, as with any Christie "whodunnit", the story isn't quite so simple.
Last year new photos emerged of the author on the deck of a Nile steamship, during her own honeymoon to second husband, archaeologist Max Mallowan in 1931. The name of the ship was unknown.
It's a trip to Egypt which seems to share far more similarities to the Poirot mystery novel than the later 1933.
The images were discovered as part of a new exhibition in the Author's hometown of Torquay, Devon.
Curators for the Christie Archive Trust also found another image of Christie on a dig with Archaeologist friend Leonard Woolley in Syria.
A spokesperson for the Trust said they had not been seen by many people, however it was difficult to say if these were the origin of her exotic mystery stories.
"It is impossible to say when or where stories such as Death On The Nile were first imagined - she had been to Egypt in 1907 as well," they told The Scotsman newspaper.
Christie had a life-long love affair with Egypt. As a girl, the 17 year old Christie travelled to Cairo. The three month trip, based out of the Gezirah Palace Hotel, would be her introduction to exotic, luxury travel. It's also in the hotels, trains or steamships where she would observe a rotating cast of characters. It was the perfect education for a budding novelist.
Although - as far we know - none of the other guests ever killed each other.
"She observed – and that's where some of this writing came from – her ability to observe people and situations, and then make the leap, bizarrely, to murder," says her grandson James Prichard.
In an interview for the Associated Press, Prichard said it was no wonder these spaces became the settings for her books.
She was surrounded by "glamorous strangers dressed to the nines for breakfast, for lunch, for tea, for dinner – but who were they behind that theatre?"
Following the divorce from her first husband, Christie returned to Egypt and the Levant.
"She wanted a holiday and someone suggested she went on an archaeological dig in Syria," said Pritchard.
It would also be the year Christie first travelled on the Orient Express, the setting for her 1934 murder book. Mixing luxury travel and plotting serious crime, would become a pastime for her.
Murder in Mesopotamia, Death Comes as the End, and other stories would visit the real life locations that Christie would visit as an amateur archaeologist and author.
It's possible that her Egyptian honeymoon was the spark for Death on the Nile, or any one of her other visits to the region. It's impossible to pin it down to any one holiday.
It was a part of the world that formed her training as an archaeologist and as a writer of mysteries.
In the novel her fictional sleuth Hercule Poirot makes the equation between detective work and digging for artefacts.
"Your take away the loose earth," he says.
"That is what I have been seeking to do—clear away the extraneous matter so that we can see the truth."
A lady vanishes: Christie's real life mystery
In 1926 Agatha Christie was reported missing. The writer's car was discovered in an abandoned chalk quarry, along with her driving licence and clothes.
Already a well known crime author, speculation ran wild as to the fate of Christie. The New York Times and international press reported on the Mystery, leading to 15,000 volunteers and amateur sleuths applying to the £100 ($12000) reward.
Christie was discovered, live and well ten days later, 300km away at a hotel in Harrogate.
Curiously, she had checked in under the surname of Neele.
Theories ranged as to whether it was a nervous breakdown, a publicity stunt for her novels or an elaborate dispute with her husband.
Some speculated that Neele was a reference to Nancy Neele, a woman with whom her first husband was reportedly having an affair.