You can read the synopsis for IT here:
New Line Cinema’s horror thriller “IT,” directed by Andrés Muschietti (Mama), is based on the hugely popular Stephen King novel of the same name, which has been terrifying readers for decades.
When children begin to disappear in the town of Derry, Maine, a group of young kids are faced with their biggest fears when they square off against an evil clown named Pennywise, whose history of murder and violence dates back for centuries.
IT stars Bill Skarsgård (Hemlock Grove) as Pennywise the Clown. An ensemble of young actors also star in the film, including Jaeden Lieberher (Midnight Special), Jeremy Ray Taylor (Alvin and the Chipmunks: The Road Chip), Sophia Lillis (37), Finn Wolfhard (Stranger Things), Wyatt Oleff (Guardians of the Galaxy), Chosen Jacobs (upcoming Cops and Robbers), Jack Dylan Grazer (Tales of Halloween) and Nicholas Hamilton (Captain Fantastic).
Andrés Muschietti is directing from a screenplay adapted by Chase Palmer & Cary Fukunaga and Gary Dauberman. Dan Lin, Roy Lee, Seth Grahame-Smith, David Katzenberg and Barbara Muschietti are serving as producers, with Marty P. Ewing, Doug Davison and Jon Silk as executive producers. The behind-the-scenes creative team includes director of photography Chung-Hoon Chung (Me and Earl and the Dying Girl), production designer Claude Paré (Rise of the Planet of the Apes), editor Jason Ballantine (The Great Gatsby), and costume designer Janie Bryant (Mad Men).