Set decades before the events of the It films, It: Welcome to Derry digs deeper into the mythos of Pennywise the Dancing Clown. By the end of It: Welcome to Derry Season 1, the timeline gets turned inside out. From reading the book, you can interpret it a thousand different ways,” Skarsgård explained. “I'm pretty sure Stephen King doesn't really know,” Skarsgård admitted. Under the guidance of Andy Muschietti, the plan is for It: Welcome to Derry to run for three seasons, each moving further into the past.