Leave The World Behind director explains loud noise and why Archie lost his teeth

Everyone and their nan has been watching Netflix's Leave The World Behind, and clearly can't get enough of it.

The psychological-thriller first dropped on the streaming platform last Friday (8 December) and viewers have been obsessed with all the hidden meanings, metaphors and symbolism sprinkled throughout the flick.

Well, luckily for such dedicated fans, some of the mysteries have been cleared up by the film's director, Sam Esmail, who has explained the iconic loud noise and why Archie lost his teeth.

The official premise for Leave The World Behind reads: "A family vacation on Long Island is interrupted by two strangers bearing news of a mysterious blackout.

"As the threat grows more imminent, both families must decide how best to survive the potential crisis, all while grappling with their own place in this collapsing world."

Boasting a star-studded cast including Julia Roberts, Mahershala Ali, Ethan Hawke, Myha’la and Kevin Bacon, Esmail both directed and produced the film which is based on the 2020 novel of the same name by Rumaan Alam.

In case you've not yet watched it, the plot follows a family of four who leave New York City to spend some time in a remote(ish) town.

From that point on, a whole lot of weird stuff goes down from crashing planes and creepy drones dropping sinister flyers to malfunctioning driverless cars and deer everywhere.

Netflix

At one point in the film when the character of Amanda (Roberts) is out in the woods, a deafening noise comes out of nowhere.

And, just the next day, her son Archie (Charlie Evans) falls severely under the weather with his teeth quite literally falling out his mouth.

Lovely image, that.

While the two odd events seem unconnected at the time, the character of Danny (Kevin Bacon) suggested a possible connection between them.

He suggests it could be the result of something called Havana Syndrome, a phenomenon that saw ultrasound and microwave weapons used to attack US government officials.

One of the symptoms, he says, is a loss of teeth.

Esmail has since addressed whether the bizarre syndrome was in fact an inspiration for the noise.

Netflix

Speaking at the Netflix Tudum event, he said: "When I read that in the book, I immediately got excited and spoke to my sound designer who I’ve worked with since the first season of Mr. Robot, Kevin Buchholz.

"Before we shot a frame of the film, we were trying to dial in this sound. We took elements of Havana Syndrome, which is a mysterious sound that they still have not gotten to the bottom of that has been causing people to have ailments."

And if you fancied an extra little Easter egg, Esmail also kept the noise a bit of a secret from the cast to add that extra level of realism to the film.

"I didn’t even tell them I was going to play it while we were shooting the scene," he explained.

"I believe Julia was the first one to have heard it, so when we did her close-up and that moment came, we blasted the sound and that was her genuine reaction."

When asked by Vulture what caused Archie's teeth to fall out, Esmail responded: "I want to be careful how I answer this.

"I think it’s a nightmare. I think the movie’s a nightmare, and I think that, in nightmares, things happen that are inexplicable."

Leave The World Behind is currently available to stream on Netflix.