The House with a Clock in Its Walls is a 2018 American family fantasy film directed by Eli Roth, based on the 1973 novel of the same name by John Bellairs. The film stars Jack Black, Cate Blanchett, and Owen Vaccaro, and follows a young boy who is sent to live with his uncle in a creaky old house. He soon learns it was previously also inhabited by a nefarious entity.
After his parents are killed in a car crash, ten-year-old Lewis Barnavelt moves to live with his uncle Jonathan. All he has left of his parents is a Magic 8-Ball they had given him. He meets Jonathan’s neighbor and best friend, Florence Zimmerman.
During the night, Lewis is puzzled when he hears a ticking sound in the walls. Lewis begins exploring the house and stumbles upon Jonathan smashing a wall with an ax. Frightened, he runs away and stumbles upon multiple household objects coming to life. Jonathan confesses that he is a warlock and Florence is a witch. The house’s previous owners were a sinister warlock named Isaac Izard and his equally wicked wife Selena, who had hidden a clock within the walls of the house before they died. Jonathan has been trying to find it and discover its purpose. Despite Jonathan’s discouragement, Lewis begins teaching himself magic.
On his first day at his new school, Lewis meets Tarby Corrigan, who befriends him in order to win an election for class president. When Tarby wins his election he abandons Lewis.
Lewis’s mother visits him in a dream. When he laments that Tarby does not see him as a friend, she suggests that he use a spell from a forbidden book to impress Tarby. So on Halloween night Lewis performs a necromancy spell in a cemetery, accidentally summoning the ghost of Isaac.
Lewis spies Isaac in the house of a neighbor, Mrs. Hanchett. He brings her to the house, but before he can find Jonathan, Isaac emerges. He reveals that Mrs. Hanchett is really Selena, who killed Mrs. Hanchett and took her place. It was also she who took the form of Lewis’ mother to persuade him to summon Isaac. Isaac explains that that his hidden clock will turn time back so that humanity never existed. Florence, Jonathan, and Lewis run from the house.
Using the’ Magic 8-Ball to learn the location of the clock under the boiler room, the three return, but Florence is sidelined, and the Izards transform Jonathan into a half baby-half adult. Lewis consults the Magic 8-Ball, which says “Say goodbye.” He realizes he has to let go of the pain of losing his parents to harness his true power. He breaks the clock by dropping the ball into its gears; then, using his own magic, he blasts Isaac and Selena. They fall, de-age, and are ultimately erased from existence.