“IT: Welcome to Derry”, a prequel series to the 2017 film “It”, is a gruesome, mystery-laden horror packed with Stephen King’s signature themes. The series, co-developed and directed by Andy Muschietti, features unsettling scenes that may not be for the faint-hearted. Despite its horrors, it’s deemed solidly entertaining, although not the best adaptation of King’s work. The show aired on Sky Atlantic and is available on Now in the UK, and HBO Max in the US and Australia.