It was based on the 1973 novel of the same name by John Bellairs, which was the first in a series of 12 books. The film follows a young boy, Lewis Barnavelt (Owen Vaccaro), who is sent to live with his uncle, Jonathan, in a creaky old house. He soon learns it was previously inhabited by an evil Warlock. From the 2018 film The House with a Clock in its Walls, this is one of the bone keys seen though out many parts of the film. Thanks to Lewis’ genius, they’ve figured out that Isaac Izard’s (Kyle Maclachlan) death, caused by a demonic ritual, created a bone key supposedly from Mrs’ Hanchett’s bones. The key opens the clock which allows him to turn back time and ultimately erase humanity from existence.