If you haven't seen the hit thriller Split yet, there will be SPOILERS below. While January isn't typically a month associated with box office hits, Universal and Blumhouse's thriller Split was one of the rare hits released during that month. The thriller, which was produced for just $9 million, earned over $274 million worldwide and was a critical hit as well with fans and critics alike praising the film. Writer-director M. Night Shyamalan has since revealed that he is working on a follow-up, with the filmmaker revealing over the weekend that he's almost done writing it, but the ending has him terrified.

At the end of Split, a post-credits scene revealed that the movie is set in the same universe as his hit 2000 thriller Unbreakable, showcasing a scene where Bruce Willis return as David Dunn from Unbreakable. The filmmaker later revealed he almost included scenes in the movie that would have alluded to David Dunn fighting Samuel L. Jackson's Mr. Glass in the movie, but he decided to take them out and save the big reveal for the post-credits scene. The filmmaker also confirmed earlier this year that he has started writing the script, and yesterday he took to Twitter to confirm he's about to write the ending, which has him terrified. Here's what he had to say below.

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"Writing climax of the new film. Had to step away. Heart pounding. Too scared and worried for the characters. Writing really is like acting."

The director teased that the Split post-credit scene was almost much different, teasing that it was, "graphic images of The Beast and then David Dunn and then Elijah and then them all mixing together." While he thought the scene was a "home run" on its own, when he put it in the movie, it just didn't work. Instead, he crafted a post-credit scene that is set in a cafe, with patrons discussing The Beast case while watching a news report. One patron is reminded of another criminal with an unusual name, where we finally see David Dunn, who reveals the criminal she's thinking of is Samuel L. Jackson's Mr. Glass.

The filmmaker previously confirmed on social media that he has an 11-page Split 2 outline completed, while stating that he almost had several other Unbreakable Easter Eggs in Split, but he took them out because they began to "take over" the movie. James McAvoy has also teased in interviews that he will be back as Kevin Wendell Crumb, with M. Night Shyamalan confirming on a recent podcast appearance that Samuel L. Jackson will be back as Mr. Glass. Take a look at this latest tweet from M. Night Shyamalan regarding the highly-anticipated Unbreakable 2, which the director has confirmed as his next movie.