IT director Andy Muschetti has credited the film’s amazing success to the connection audiences feel with the main characters. IT has become one of the highest grossing horror films of all time and has taken over $370 million at the global box office, after only its second week of theatrical release.

The film has given the box office a much-needed self-esteem boost after a rough summer, where a number of potential blockbusters (like King Arthur: Legend of the Sword, The Mummy and The Dark Tower) failed to make an impact. IT is currently expected to surpass $300 million by the time it exits cinemas in North America - a feat that’s doubly impressive for an R-rated horror flick.

Related: IT Producer Reveals Which Scene Scared Stephen King

In a new interview with io9, Andy Muschetti and producer sister Barbara credit IT’s success to the emotional bond viewers form with The Losers’ Club during the story:

“I don’t think [audiences] quite expected such an emotional connection with the story. That’s what I take from, not only working on the movie but the reactions. When I hear them, and I read them, people are very attached emotionally to the journey of these kids. Which is not really frequent for horror movies.”

The sibling duo snuck into a theaters screening of IT on opening night to see how audiences reacted, and even they were surprised by how involved the crowd got. Barbara Muschetti even compared the response to some classic Spielberg movies.

“We kept on looking back to see the reactions, and of course, people were terrified at moments and laughing at other moments. But mostly, through the film, they had faces of joy. There was wonder in the room. They were smiling. That is what we remembered when we would see films like Close Encounters or Back to the Future, people just experiencing joy in a room packed with people. And there’s nothing like that.”

The duo also touched on the reaction to The Dark Tower, the other major King adaptation that came along in 2017. The long-anticipated movie version of the author’s sprawling fantasy novels had some fans, but was ultimately a critical and commercial dud, and it looks like a planned television series may not happen after all. The Muschetti siblings feel IT was always going to be an easier film for audiences thanks to its emotional grounding, which The Dark Tower lacked:

“The Dark Tower is much less relatable, especially at the start of the story. In The Dark Tower, we’re almost immediately invited to jump into this world of fantasy.

Andy continued:

That doesn’t mean a lot of people won’t like it. It’s just more genre, I think, and you can’t expect a massive audience to eagerly jump into that reality.”

NEXT: Why Horror Movies Are Hitting It Big in 2017

The Muschettis are currently working on IT: Chapter Two, which is expected to hit theaters in 2019.

Source: i09