'It' sequel: See first photo showing the grown-up cast with James McAvoy, Jessica Chastain

Bryan Alexander | USA TODAY

Show Caption Hide Caption Trailer: 'It' An evil entity haunts a small Maine town every 27 years in the form of a killer clown in the horror film 'It.'

Evil and a certain horrifying clown are resurfacing in "It Chapter Two."

Production started Monday for the sequel to the 2017 film adaptation of Stephen King's "It," the highest grossing horror film of all time with more than $700 million worldwide.

The follow-up will be in theaters Sept. 6, 2019.

We learned in "It" that evil revisits the town of Derry, Maine, every 27 years. So “Chapter Two” brings the characters — who’ve long since gone their separate ways —back together as adults, nearly three decades after the terrifying events of their childhood.

Naturally, this means the terrifying clown Pennywise (Bill Skarsgård) is back. James McAvoy stars as grown-up Bill, Jessica Chastain as Beverly, Bill Hader as Richie, Isaiah Mustafa as Mike, Jay Ryan as Ben, James Ransone as Eddie, and Andy Bean as Stanley.

Chastain already featured a look of her Beverly on Instagram.

"It" director Andy Muschietti returns to helm the new film, based again on the King novel.

Warner Bros. released a photo of the grownup cast during a script read. They all seem happy, for now. That won't last.

More: Review: 'It' does justice to freaky horror and youthful zest of Stephen King's novel

Also: Stephen King's creepy cool 'It' obliterates box-office records with $117.2M

Bill Hader (as Richie) should start working on his scared face.

The original members of the Losers Club from the first "It" are also returning: Jaeden Lieberher as Bill, Wyatt Oleff as Stanley, Sophia Lillis as Beverly, Finn Wolfhard as Richie, Jeremy Ray Taylor as Ben, Chosen Jacobs as Mike, and Jack Dylan Grazer as Eddie.