Warner Bros. Discovery on Friday released the first official poster for “IT: Welcome to Derry,” a prequel series that expands Stephen King’s “IT” universe. The eight-episode show is slated to premiere in October on the company’s streaming service, currently branded as HBO Max. Set decades before the events of the hit 2017 and 2019 films, the series is expected to explore the origins of Pennywise and the town’s cycle of terror. Cast and specific plot details have not yet been disclosed, but the marketing rollout signals that production remains on track for the fall debut.