‘The Woman in Cabin 10’ Twist and Ending Explained: What Was Changed From the Book?

“The Woman in Cabin 10” is now streaming on Netflix and, like many movie adaptations of books, it makes some key changes — particularly when it comes to the twist of the story.

This perhaps goes without saying, but just so we’re clear, there will be very large spoilers ahead for the film.

Based on Ruth Ware’s book of the same name, “The Woman in Cabin 10” stars Keira Knightley as Laura “Lo” Blacklock, a journalist who gets invited aboard a superyacht to cover a charity event held by the uber-wealthy to support cancer research. But, after seeing someone go overboard in the night, she’s gaslit by everyone onboard, after all passengers on the manifest are accounted for.

The thing is, thanks to her job, Lo very recently saw a woman get murdered for agreeing to speak with her on a story. So everyone onboard the yacht insists that Lo was imagining things based on her trauma. The journalist is 100% certain about what she saw, though, and that certainty was something that was important to director Simon Stone.

“I think the films that we make plant seeds of the kind of archetypes and stereotypes that we see in society,” he explained to TheWrap. “People use phrases like ‘main character energy,’ or ‘gaslit,’ or memes come from movies, TV shows. So the content that we create as filmmakers, as TV makers, is deeply influential, even if it gets misused and it wasn’t our original intent.”

Stone said he was adamant that while “Woman in Cabin 10” concerns a woman whose cries for help are not believed, he was careful about how, exactly, he told that story.

“Putting images out there, putting narratives out there that can feed into the diminishment of the believability of women is not something I want to be involved with, full stop,” he continued.

Who went overboard?

Indeed, Laura is correct. She really did see someone go overboard, and it was covered up. This is your final exit before spoilers occur!

The person she sees in the water is the fundraiser honoree, Anne, the wife of Richard Bullmer (Guy Pearce). How is that possible, considering Anne still appears to be attending events? Well, it’s a body double.

Using the facial recognition AI technology of one of the guests onboard, Bullmer was able to find a woman who looked just like his wife, reach out to her on Facebook, and bribe her to pretend she was Anne. He needed her to do so because Anne had written him out of her will, and planned to liquidate her many, many assets.

It’s a pretty big change from the book, as in that version, the woman pretending to be Anne is actually Bullmer’s mistress, and really loves him. Here, she’s just a woman who desperately needs money to support her family.

Why the change?

According to Stone, the idea to have Bullmer finding a stranger to be his wife’s body double came from his own recent travel experiences.

“This is the first time this has ever happened to me, but when I got on the plane in Hong Kong to come back here, I didn’t have to show my ticket or my passport, because they had my face,” he recalled. “So they used my face to open the gate to let me. And I was like, ‘That’s terrifying.’”

“It means that somewhere in Hong Kong, at least Cathay Pacific, has a record of my face, and if that got hacked, then everyone else has a record of my face,” he continued. “They also have all sorts of other details about me. Like, the technology is there. We’re there.”

Beyond being both terrifying and potentially easy to do, Stone argued that it’s pretty easy to pull off a switch, if the faces line up enough.

“I’ve worked in a lot of different countries, and there are some stock characters,” he said. “You will find someone who is like the best friend that you grew up with, who has the same style of humor, or has the same dynamic in a group. You will find them in lots of different environments.”

“I experienced that a lot,” he added. “And so the idea that there’s already so many faces, and there’s only so many types out there, that we are kind of genetic repetitions is both terrifying, but also nice, because there’s this kind of commonality to our existence.”

How does “The Woman in Cabin 10” end?

In the end, Cassie — which we learn is the real name of the doppelgänger — opts to help Lo escape, and manages to get home safely to her daughter too. In the book, the woman simply takes her money and disappears, but in the movie, she remains in contact with Lo, encouraging the journalist to come visit.

Meanwhile, Bullmer is taken out by a tag team of Lo and Nissen (Amanda Collins), as he tries to take Cassie hostage. So, in the end, the bad guy truly loses.

“The Woman in Cabin 10” is now streaming on Netflix.