*WARNING: SPOILERS FOR SPLIT*

M. Night Shyamalan has confirmed he's already working on a sequel to Split, after the James McAvoy-starring horror proved a surprise box office hit, landing the director his first number one in over a decade. With $141 million in the bank thanks to its global takings, it was almost inevitable that the film would be delivered a second outing, especially considering how neatly that ending delivers franchise opportunities.

"I have an 11-page outline for my next film in the bag. I can't tell you what it is, but if you've seen Split...," Shyamalan tweeted out. That seems an obvious indication as to where any future Split installment may go, though the project the director is hinting at may even be Unbreakable 2, considering Bruce Willis' cameo in Split's final scene immediately integrates the film into the Unbreakable universe.

Indeed, Shyamalan previously revealed McAvoy's character Kevin - who has 23 different personalities - was originally conceived as a character for Unbreakable.

"The original draft of Unbreakable focused on David Dunn and Elijah as his mentor," he explained. "Elijah tells him, ‘You’re a comic book character, go try it.’ And instead of bumping into the Orange Suit Man, David bumps into one of Kevin’s personalities and goes to save the girls. So you’d have been watching the girls side of it the whole time. That was the outline."

Split - Trailer 2