If you ever fear that a social situation might take a murderous turn, here’s a quick tip to help you determine if everything is above board: How is the service? Is there something wrong with the wait staff? Are the landscapers staring uncomfortably in your direction? Do the nurses on duty all seem to be in on some big secret? If the answer is yes, you’d better get out of there immediately. You’re in danger.

The strange behavior of service employees has now become a hackneyed cliché in the horror genre, escaping simple horror cinema (as helpfully described by The cabin in the forest as a signpost warning of the victims of a horror film) to more pointed films that deal with class or personality from the perspective of a genre (Exit, The menu, Ready or Not). You know how it goes: The smartest of the unwitting main characters notices that the help that is normally used to stay in the background is only a little out ofa telltale sign that not everything is as it seems. Exitthe protagonist Chris (Daniel Kaluuya) notices that the maid Georgina (Betty Gabriel) is acting strangely, which is his first clue that something is wrong with his white girlfriend’s family, but at least this film actually cares about the fate of its housekeeper, making her destruction at the hands of the Armitage family the film’s gruesome subject. Other films that use this stylistic device are not as thoughtful and like to rely on the cliche of highlighting creepy service staff while ironically ignoring their personalities.

Flash twice is the latest horror film to do so. Zoë Kravitz’s thrilling debut thriller, which premieres August 23, follows Frida (Naomi Ackie) and Jess (Alia Shawkat), best friends who happen to be on an idyllic island vacation with tech billionaire Slater King (Channing Tatum) and his sidekick. The film makes no secret of the fact that something is wrong – if you don’t mistake it for a mere hangout flick, Flash twice sets you on the right track right away when a housekeeper starts cryptically shouting “red rabbit” at Frida, one of the few lines a service worker gets in the film. This will happen again, among other odd behaviors that Kravitz constantly points out, including snake-killing, blank stares, and broken English.

Considering how Flash twiceThe protagonist and her best friend are both waitresses themselves—party caterers who, after dressing up in cocktail dresses for fun, are suddenly whisked away to an island for the super-rich—you’d think the film would be interested in examining the plight of the waitresses with some nuance in relation to the horrors unfolding on the island. The creeping sense of dissatisfaction that Frida and Jess feel as their time in paradise progresses presumably stems from their discomfort among the one percent. But then the film eventually reveals that none of the female guests present know each other, and at the heart of the mystery lies something else entirely. The sinister wait staff who have given the characters and the audience the most important clues fade into the background again as the women investigate what this island hides.

When Flash twice takes its big, bad turn – I don’t want to give anything away here, but trust me when I say that this will single-handedly determine whether you like the film or not – there are still many questions left unanswered about the staff who tipped Frida off: Are they also victims of the film’s dark secret? Are they conspirators? Do they even survive the credits? But these questions remain unanswered because the helpers are practically ignored, even though the events of the story would not have been possible without them.

There’s a reason this stereotype of creepy service workers as a sign that something is wrong is so effective in horror movies: After all, they are people whose job it is to go unnoticed. But this shortcut only works if you buy into the unsettling idea that certain people are inherently unnoticed. It speaks to a deeply ingrained cultural attitude that acknowledging a service worker’s personality goes beyond what the social contract demands and does not constitute a baseline of respect.

This is annoying in a film like Flash twicea film whose final twist revolves entirely around the belief that some characters’ personalities are worth more than others’, and taking revenge on people who hold those beliefs. When the central conflict of your story is between people who assert their agency and those who deny it to them, ignoring an entire group of people undermines the entire point of the story. Service work, as it largely exists in this country, is immoral; a career that demands the complete and total sublimation of one’s self should not be predominantly the preserve of our weakest and most underpaid workers. Flash twice and other films like this don’t even let these people Characters.

Of course, a film cannot name all the characters that appear on the screen and give them all an exciting story, but it may express a negative opinion of an entire social class, a preference for certain parts of society and a disinterest in others. Flash twice has something more in mind than the flood of thrillers we have seen recently, like Saltburn or The menuand ultimately makes it clear that he is primarily concerned with powerful men and how they use their power to satisfy their insatiable appetites at the expense of others.

But who are the others who are avenged? It is not the landscapers and maids who never speak, and if they did, their language would be neither understandable nor translated. The film has no time for them. Flash twice ends as it began: at a party for the rich, in a gallery full of waiters and catering services. This time everything is back to normal. Nobody notices the help.