“Fifty Shades of Grey” is now officially a box office phenomenon — raking in an estimated $266.4 worldwide in its first weekend. The movie’s final shot, which features Christian (Jamie Dornan) and Anastasia (Dakota Johnson) at opposite sides of a closing elevator door, clearly sets the stage for a sequel (“Fifty Shades Darker”) and third film (“Fifty Shades Freed”), which could even be divided into two movies (see the last installments of “Hunger Games,” “Harry Potter,” “Twilight” and “Divergent”). Yet Universal has yet to officially announce a greenlight for more “50 Shades.” How come?

One possible theory: The studio is waiting to line up a director first for the next film. Over the weekend, British tabloids reported that director Sam Taylor-Johnson — now the most successful woman director to open a film in the United States — wouldn’t be back for a second film. On Monday, the director’s rep offered a carefully worded denial to Variety: “All press reports are pure conjecture as the studio has not committed to a sequel as yet.”

Here are six questions about the next film.

Will Sam-Taylor Johnson direct it? By most accounts, the shoot for “Fifty Shades” was difficult. Author E.L. James, who negotiated a deal to retain creative control over the bigscreen adaptation, constantly locked horns with Taylor-Johnson throughout the 10-week shoot and in the editing room. “We disagreed a lot,” Taylor-Johnson told Variety in January. When asked if she’d direct the sequel, Taylor-Johnson didn’t sound enthusiastic. “I feel like I never want to make a movie again,” Taylor-Johnson said. “Maybe that will possibly change soon.”

Who will write the script? The first film was credited to Kelly Marcel (“Saving Mr. Banks”). But her initial pass underwent revisions by Patrick Marber to tone down the sexual content, and Marcel has also been suspiciously absent from the “Fifty Shades” press tour. In July, The Tracking Board reported that Universal was looking for a new screenwriter to tackle the next film, but it’s unclear if the studio has found someone to work on the story yet.

What about the cast? Stars Dakota Johnson and Jamie Dornan are already committed to sequels, as part of their contracts to enter the BDSM world of “Fifty Shades.”

When will the movie shoot? Without a script or director announced, it might be hard for Universal to start filming immediately. Then again, Universal might want to rush the sequel — like Summit Entertainment did with the first “Twilight” film — to take advantage of audience interest. Over the weekend, “Fifty Shades” received a lousy C-plus CinemaScore, meaning it would be better for the sequel to open sooner rather than later. It could also mean that because fans were disappointed, creative elements of the story need to be rejiggered to keep ticket buyers satisfied.

When will the movie open? If the studio is able to fast-track a script, and the movie shoots over the summer, there’s a chance that “Fifty Shades” would open next Valentine’s Day weekend — where it would go up against “Deadpool” and “Gods of Egypt” — to capitalize on the same window that made the first movie a hit. But if the filmmakers don’t want to rush it, “Fifty Shades Darker” could also debut in the summer of 2016, where it would offer strong counterprogramming to all the action tentpoles targeted to teenage boys.

Will the sequel be steamier? The second and third books from E.L. James are even more explicit than the first. Now that Universal has proven sex sells at the box office, the other movies could push the envelope further in terms of what happens in Christian’s Red Room. “I don’t know why people are so offended by nudity,” Dornan told Variety in January. “It’s not something that offends me.”

Brent Lang and Leo Barraclough contributed to this story.