The elusive logline reads: "Set in the world of Stephen King's ‘It' universe, ‘It: Welcome to Derry' is based on King's ‘It' novel and expands the vision established by film

Set in Maine in 1962, Welcome to Derry functions as a prequel to the It remake duology released in 2017. Andy Muschietti, director of the two It films, is the writer for Welcome to Derry and will direct a number of the series’ episodes. Bill Skarsgard is also returning to reprise his role as Pennywise.

"Get ready to go back to where IT all began..." reads HBO's tagline, suggesting It: Welcome to Derry presents the morbid origin story of Pennywise. Set in the 1960s, the plot centres on a group of young people exploring the mystery of an evil force that has been terrorising the town of Derry for centuries.