'It Chapter Two' Trailer Launch Kicks Off Comic-Con

New Line's third annual ScareDiego revved up the scares (and laughs) as Conan O’Brien brought out Andy Muschietti, Jessica Chastain, James McAvoy, Bill Hader and others to share secrets from the horror sequel.

Scares took center stage at San Diego Comic-Con on Wednesday as New Line unveiled a new look at It Chapter Two, the company’s sequel to the biggest-grossing horror movie of all time.

The audience got an early look at the new trailer, which debuted online Thursday morning. The presentation, taking place on Comic-Con’s preview night, is dubbed ScareDiego and is held off the San Diego Convention Center grounds, and unofficially kicks off the Con in terms of movie panels. The event, now in its third year, is growing and this year was held at the Spreckels Theatre with comedian and late night show host Conan O’Brien serving as moderator.

Chapter Two focuses on adult characters as opposed to the first movie, which was set in the 1980s and told of a group of kids dealing with a murdering demon clown named Pennywise. Joining O’Brien on stage to discuss the Stephen King adaptation was director Andy Muschietti and actors Jessica Chastain, James McAvoy, Bill Hader, Jay Ryan, James Ransone and Isaiah Mustafa.

Despite the subject matter (a horror movie), and the clips shown (a first look at the new trailer and three creepy scenes), the panel was heavy on laughs, thanks to Hader and the easy rapport between Chastain and Muschietti, who at one point cajoled the actress into a duet of "Tonight You Belong to Me."

But the evening did provide some insight into the upcoming movie.

Muschietti said that he began casting the sequel in his head while shooting the first movie: “During the production we started playing with names and speculating who would play the [adult] counterparts.

"I was very lucky that I got everyone I wanted to play in the movie…. Half the cast was pre-thought about it. And the rest auditioned," said the filmmaker.

The cast spoke about each receiving personalized letters from the young actors who played their characters in the 2017 film. The letters — written to their future selves — also came with a framed photograph of each young actor, noted Hader. It was a sweet gesture, but funny, too.

"I think we all had the same thought at the same time: 'there's no way I'm going to put up a picture of a young boy,' " Hader said to laughs.

Chastain revealed that over 4,500 gallons of fake blood was used during production, most of it on her for the movie’s third act. She frequently went into a kiddie pool to pour on the blood, a concoction which was kept at a very low temperature to prevent from curdling in between takes. The actress apparently really got into the scenes, at point telling the director, “let’s make Carrie on steroids.”

Muschietti was happy to oblige when it came to intensity, with the filmmaker demanding take after take from his cast. McAvoy noted that there was a particular scene requiring him to fall on his knees. He shot it over and over, to the point where McAvoy had tendonitis for six months after the shoot.

"Then you see it in in the trailer, and it looks amazing…for about a tenth of a second," McAvoy said to laughs from the crowd. "It could have been my stunt double, because I swear to god, you'd never know it's me."

But Muschietti noted he had good reason to push his actors for more takes.

“It’s because I want an option," said the filmmaker.

Chastain then recalled a scene she was shooting take upon take, not quite pleasing the director and getting a little bit frustrated. “‘I don’t know what you want,’” she recalled saying. “‘What do you want?!’”

“I want everything!” she said Muschietti responded, in a gravely dramatic tone.

In addition to a scene of the Losers Club reuniting at a Chinese restaurant  and another to confront Pennywise, the audience was treated to a scene of McAvoy's Bill traversing a funhouse, attempting to rescue a young boy from Pennywise. McAvoy revealed the initial sequence didn’t even have his character in it. The actor, feeling his character needed to address a beat in his arc dealing with survivor’s guilt, talked to the filmmaker about his concerns and Muschietti came up with ideas to alter a funhouse idea on the spot. “It was a conversation that lasted about an hour,” McAvoy said, then snapped his fingers in the air three times and finished flourishingly with a pop sound.

“It was brilliant to see that over tequila," said McAvoy.

It Chapter Two opens Sept. 6 from Warner Bros. and New Line.