The Woman in Cabin 10 belongs to a subgenre that goes back to the Vanishing Hotel Room urban legend. In it, a daughter leaves her sick mother in a hotel room to get out and get her medicine. By the time she returns, her mother is nowhere to be found. Worse, everyone insists that her mother was never there to start with. Sometimes, even the room itself.

It has been remixed and reinterpreted for years in numerous films, TV shows, books, and plays. In America, the most recent well-known example is the similarly titled The Girl on the Train, which proved a wildly successful beach and airport read by Paula Hawkins and a financial, but not exactly critical, success. The Woman in Cabin 10, also an adaptation of a novel, written by Ruth Ware in this case,skips the box office question entirely by being a Netflix release. Critically though? Their fates are similar. But similar does not mean the same.

Train, despite an impressive cast, was a misfire from nearly jump. The Woman in Cabin 10, on the other hand, makes an admirable go of it until it loses the courage of its premise.

Lo Blacklock (Keira Knightley) is a journalist looking to escape the trauma of a recent story by diving into work. She gets the opportunity when an invitation to an unconventional charity event lands on her desk. Billionaire Anne Bullmer (Lisa Loven Kongsli), dying from terminal cancer, has, along with her husband Richard (Guy Pearce), invited several of her rich friends to a cruise on their super yacht that culminates in a fundraising gala in Norway. Rich people do things differently, in case you weren’t aware.

Depending on how cynical you are, either to spread awareness or to ensure everyone knows how altruistic they are, the wealthy want a journalist on board to chronicle the whole thing. Lo’s editor Rowan Lonsdale (a criminally underused Gugu Mbatha-Raw) urges the writer to take a break. Her efforts to encourage good mental health hygiene are perfunctory at best, though, so Lo brushes them with little hesitation.

Her ex, photographer Ben Morgan (David Ajala), also ends up on board, so maybe Lo should’ve taken Rowan more seriously. (Listen to your editors, PEOPLE!).

The richies onboard include the likes of bloviating Adam (Daniel Ings) with his date, social media influencer Grace (Kaya Scodelario), and the vaguely but deeply disconcertingly sexual married couple Thomas (David Morrissey) and Heidi Weatherly (Hannah Waddingham). They largely don’t have complex personalities, but occasionally get moments to take center stage. Morrissey makes a meal of his best line regarding how he’s the one who ends up bruised after arguments with his wife, but Waddingham gets the most overall as she gets to play not just haughty superiority but, briefly, genuine fear. Plus, she REALLY nails haughty superiority.

The film sets this table slickly under Simon Stone’s direction. He and cinematographer Ben Davis can’t quite overcome the Netflix aesthetic, but they offer perhaps the best possible utilization of the form. The script by Stone, Anna Waterhouse, and Joe Shrapnel, with an additional adaptation credit to Emma Frost, reduces most characters outside of Lo to types, but they also keep things moving. The vibe isn’t tense, per se, the moment we get to the ship, but it is uncomfortable and unnerving. Even before the mystery of the titular Woman, it is clear this whole endeavor is off at best.

And then the mystery arrives.

The reveal and subsequent apparent disappearance of The Woman in Cabin 10is well done. Knightley has developed a talent for hypercompetent types who most nonetheless dismiss in films like The Boston Strangler and shows like Black Doves. (It makes her apparent flippancy about certain boy wizard-related material all the more disappointing.) The way she works her mouth to convey shock, horror, and mounting desperate frustration is impressive.

The problem is that the film abandons the question of what is real, what is a conspiracy, and what might be a delusion far too quickly. Worse, the moment it does, the film unravels. To make it work, it literally hides its lead in the ship’s bowels, sidelining the only character with three dimensions. Gitte Witt helps some as a late-arriving character, Grace. However, she lacks the depth of Lo and doesn’t get enough time to add layers. With the loss of the mystery, so too goes the unnerving vibes. What felt like an “it’s impossible to know who to trust” situation degenerates into a bunch of rich folk gossiping about the mental health of one of the only people on board who has to work for a living. To be blunt, it goes from spooky to catty in a blink.

Pearce makes a last-minute attempt to save the whole thing with a game bit of scenery chewing, but it’s too little too late. As credits roll, there is a distinct lingering sensation of “oh…is that it?” It isn’t that things don’t wrap up, but rather that they do so cleanly, so blandly that The Woman in Cabin 10 is already evaporating from your mind as you reach for the remote.

The Woman in Cabin 10 has settled in by the pool on Netflix now.

The Woman in Cabin 10 Trailer: