'Sixth Sense' mastermind M. Night Shyamalan reveals his secret to surprising the audience

It has been 20 years, but we’re still shook by the twist ending of The Sixth Sense, M. Night Shyamalan’s breakthrough 1999 horror blockbuster. In its haunting final moments, the movie makes the leap from a spooky, atmospheric ghost story about a young kid (Haley Joel Osment) who can see the undead to a deeply emotional — and altogether surprising — meditation on life, death and love.

That finale is what brought people back to the cinema again and again two decades ago, propelling The Sixth Sense to a nearly $700 million worldwide gross, as well as multiple Oscar nominations including a rare horror movie Best Picture nod. It also made Shyamalan’s name synonymous with third-act plot twists, a device he’s continued to employ (sometimes successfully, sometimes not) in movies like Signs, The Village and this year’s hit Glass.

Speaking with Yahoo Entertainment back in January for that third installment in his comic book-inspired trilogy (the previous entires were Unbreakable and Split), the filmmaker reflected on the foundational lessons that The Sixth Sense taught him about how to spring a surprise on the audience.

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“Really, it’s a format of how tell the story,” Shyamalan explains of the big reveal that Bruce Willis’s kindly child psychologist has been a ghost all along. (Watch the video above.) “You pull back and you see the full mosaic, and you go, ‘Whoa, that was the eye in the face? I thought that was the whole person!’ And it’s actually a person inside of an eye inside of a face. You’re seeing the bigger picture at some point in these stories.”

Behind the camera, The Sixth Sense was occasionally as frightening an experience for Shyamalan as it was Osment’s dead people-seeing boy. At the time, the director was coming off two barely released movies, 1992’s Praying With Anger and 1998’s Wide Awake, and was working at a major Hollywood studio (Walt Disney) with a major movie star for the first time in his young career.

On the first day of shooting, he had the kind of encounter with his leading man that would send many directors to their trailers trembling with fear. “We were waiting for a cloud to pass over, because the light was too strong,” he remembers. While Shyamalan was willing to wait for the right light, Willis didn’t share his patience.

“He came up and was like ‘What are we waiting for?’ I said, ‘The cloud.’ He was like, ‘We can’t just sit around waiting for clouds, kid.’”

Eventually, the cameras rolled and production continued without incident. At the end of the first week of filming, though, Willis summoned Shyamalan to his trailer.

The director nervously knocked at the door, and his star answered. here’s the twist: “He said, ‘The last time I felt like this was Pulp Fiction and Quentin Tarantino,” Shyamalan says, still visibly relieved 20 years later.

“He was like, ‘You got it, kid.’ He closed the door and I was skipping down the sidewalk!” And we all lived happily ever after.

The Sixth Sense is currently streaming on Netflix.