Since "Sinister" tapped into that Blumhouse Productions magic by grossing $62 million on a $3 million budget (and thus following in the footsteps of "Paranormal Activity" and "Insidious"), it's no surprise that the studio is already thinking about a sequel. Both director Scott Derrickson and screenwriter C. Robert Cargill also know that such talk is inevitable, and the duo has mused about the possible direction a follow-up could take.
In an interview with SciFiNow, Derrickson confirmed that they're "in the process" of exploring those possibilities. The director also expressed his desire to stick around as a screenwriter and to serve as a producer, but he didn't rule out the possibility of also directing a sequel.
Derrickson insists that he can't see himself "just handing the franchise over to just anybody and letting it go," as he wants to "see it start its process on the right foot at least and always have some say and have some involvement in it."
Cargill revealed that he and Derrickson were already having conversations about a sequel during production on the first film, where the two "had discussions" and "spitballed" ideas that they would like to do if the opportunity for a sequel ever presented itself.
Like Derrickson, Cargill is keenly aware of how horror franchises have operated in the past. However, he revealed that he's "in two different minds" when it comes to sequels, as he does have "concern" about "trying to find new ways to do the same story again."
At the same time, though, he realizes that "audiences really love their horror sequels and will keep watching them over and over again until it's been completely run into the ground." The screenwriter then pointed to the "Paranormal Activity" series as a good example, as he noted that "twice as many people" went to see that franchise's fourth installment a week after "Sinister" was released.
As such, Cargill sees the value in wanting "to do something new and different," but he also believes it's important to "give the audience what they want." Ultimately, though, Cargill believes the film has to be "good enough to warrant" its existence.
Given Blumhouse's track record, it seems likely that there will be a second "Sinister" film. The company already has "Paranormal Activity 5" and "Insidious Chapter Two" in production, so don't be surprised if these two films are eventually joined by a follow-up that charts the further exploits of Bughuul.

