How Split director M. Night Shyamalan and other mystery-film makers stop plot twists leaking out in social media age

Just imagine if social media had been around in 1999 for M. Night Shyamalan’s The Sixth Sense: Everybody breaking down its twists, opening-day memes with Bruce Willis as a ghost, the inevitable hashtag #ISeeDeadPeople.

Back then, it was easy for filmmakers to make a movie with secrets and surprises galore. In 2017, it’s tough making it to opening night with all its twists intact, though that hasn’t deterred Shyamalan, whose new thriller Split arrived in cinemas this week.

“I feel the way to make box office for me is to make the most unique movie of the year,” says Shyamalan, who became a Hollywood wunderkind in the early 2000s with his cinematic surprises. “I need you to feel like if you don’t see Split, there’s no way you can guess what the feeling of seeing Split is. And that creates an urgency to go.”

So far, so good for keeping the reveals – including one that will wow old-school fans – under wraps for Split, which centres on three teenage girls kidnapped by a man (played by James McAvoy) with 23 personalities. Shyamalan owes that to “this incredible conspiracy of kindness” from crowds who’ve seen it early at Austin’s Fantastic Fest in October and other screenings since. But it’s just one of several recent movies that has figured out how to keep its story or very existence on the down low.

“It’s so hard these days to contain any sense of secrecy, especially in something that is so collaborative like film work,” says Jeff Bock, senior box-office analyst for Exhibitor Relations. “You’re talking about production assistants or just set visitors who have their phones on them and can take pictures. How many people are you going to have to gag to make sure the secrets stay?”

One way to do it is to avoid talking to the media. Paramount denied requests to interview filmmakers involved with God Particle (out October 27), the upcoming third Cloverfield film starring David Oyelowo, Gugu Mbatha-Raw and Elizabeth Debicki that involves astronauts in terror. Bock calls the original 2008 found-footage monster movie “the last real secret film that nobody knew anything about at all”.

Last year’s 10 Cloverfield Lane, starring Mary Elizabeth Winstead and John Goodman, was filmed under the false name Valencia. That strategy succeeded: The film’s real title and first trailer didn’t premiere until two months before its March 2016 release and the movie ended up earning US$108 million worldwide. “There’s fun in discovery,” producer J.J. Abrams told USA Today last year. “We didn’t even bring the cast in on it until the last minute.”

The actors in last September’s secret Blair Witch sequel also weren’t told of the movie’s true nature before filming, and until July it was marketed as an original horror film called The Woods. In that case, however, the smoke-and-mirrors act “worked against them”, Bock says, because it didn’t give fans enough time to get excited – it only made US$45 million globally.

“Unless you have Star Wars, the notion of not showing a movie until the day it comes out is really hard to get away with now, because everyone thinks you’re trying to hide something that isn’t good,” says Jason Blum, who produced Split as well as Shyamalan’s previous small-budget effort, 2015’s surprise hit The Visit.

Keeping the twists safe is pretty simple for Shyamalan these days. “It’s gone the opposite of what I used to do, [which was] keep everything super-secluded,” he says. “Now, I want its protectors to be the audience.”