Netflix fans floored by 'scary' detail in new Keira Knightley film

Netflix fans have tuned in in droves to the new Keira Knightley thriller, The Woman in Cabin 10, which hit the streaming platform this month after much anticipation. Based on Ruth Ware's novel of the same name, which was published in 2016, it follows Knightley as hard news journalist Laura 'Lo' Blacklock, who finds herself on board a luxury yacht's maiden voyage, rubbing shoulders with the upper elite.

The film kicks off with Lo returning to work after a harrowing experience in which she saw a witness murdered for agreeing to speak with her for a story. Her editor pushes her to take a break, but Lo is undeterred in her desire to get back to work.

When she receives an invitation to the Aurora Borealis, a swanky yacht, for three days at sea followed by an exclusive gala event, she believes this could be the ideal mix of work and play.

Initially, all seems well; Lo is welcomed into the fold by philanthropist Richard Bullmer (Guy Pearce), who's put arrangements for the trip in place to celebrate his wealthy wife, Anne (Lisa Loven Kongsli), who is dying of cancer.

We learn it's Anne, in fact, who insisted on Lo joining the group as she's a fan of her work.

Anne wants Lo to help her finetune her speech for the gala, where she's keen to announce she'll be donating her vast fortune to help those in need upon her death.

Later, Lo hears a struggle in the cabin next to hers and goes out onto her balcony to investigate. She hears a splash and sees a woman floating in the water below - and a bloody handprint on the glass partition separating their balconies.

When she demands answers, all her co-passengers - and the staff - are accounted for. With nobody supposedly missing, her recent trauma is used to dismiss her claims as a PTSD-induced dream or delusion, with the remaining guests growing increasingly impatient with her.

Despite not being believed, Lo sets out on a dangerous quest for answers.

Anne starts behaving unusually - she forgets a meeting she'd previously arranged with Lo, and despite telling everyone she's stopped taking her medication, she blames her confusion on those pills.

Eventually, it's revealed Richard used his friend's facial recognition software to find a woman to pose as Anne to re-write her will, signing her billions over to him instead of donating to charity.

The woman Lo saw chucked overboard was the real Anne, with the imposter - sporting a freshly shaven head and Anne's wardrobe - taking her place.

It was this element of the film's twist ending that unnerved some viewers - the very thought that as use of technology and AI continues, finding doppelgängers to act as stand-ins is a plausible reality.

On Reddit, one person shared: "It was good. It's refreshing to watch a movie that doesn't waste any time. What's scary is it's probably possible for someone to use facial recognition to find a doppelgänger.

"My only minor quibble with it was I would've expected her to read the room more quickly and keep her suspicions to herself. Because we all know there are no good billionaires."

Another posted: "I rewound the movie to make sure they didn't cheat by using imposter Anne the whole time, to trick us, and only using two separate actors when they're depicted in the same room together. They didn't cheat! That's what was so neat, I didn't notice the swap either. Never crossed my mind."

Others shared their opinions on the film as a whole. One person said: "People will nitpick things to death but I rather liked it. Not too long and to the point. 7/10.

"Good Saturday night movie that isn't complete trash and gives you a decent enough murder mystery with an ending that pays out."

Author Ruth Ware told Netflix's Tudum that despite the book being published almost a decade ago, its relevance endures because "the fear of not being believed is perennial, unfortunately".