Spoilers: The secrets behind M. Night Shyamalan’s surprise ‘Split’ ending

He has 23 personalities and has shown them to his psychiatrist. But there is one he has yet to expose. Now, Kevin, played by James McAvoy, has kidnapped three teenage girls and their fate hangs in the balance as time is running out.

USA TODAY NETWORK

SPOILER ALERT: The following discusses plot points and the ending of the movie Split.

Of course M. Night Shyamalan’s first sequel is also a secret one.

Really, you should stop reading right now if you don’t want to know. There are many spoilers in here.

It’s not apparent until the final scene of the filmmaker’s new thriller Split, which topped the box office with $40.2 million, that — surprise! — it’s all a follow-up to Shyamalan’s 2000 movie Unbreakable, right down to an appearance from Bruce Willis’ superhero security guard David Dunn.

And it’s not even the end of the story: Shyamalan is writing a third film that will wrap up the Unbreakable saga. “I do feel it’s important to keep making these original movies, that’s what I do, but I don’t mind this unusual trilogy existing in the group,” he says.

Unbreakable introduced Willis’ Dunn, a Philadelphia man who realizes he’s super-strong and pretty indestructible after he’s the only survivor of a horrific train crash. It also marked the debut of comic-book collector Elijah Price (Samuel L. Jackson), aka Mr. Glass, a bad guy behind many past travesties who’d been waiting years to find his do-gooding counterpart.