<P> The three return home to find the horseshoes have been pulled off the walls, indicating Isaac had returned to the house . They enter to find it ransacked . Jonathan and Florence decide to destroy the key, but it won't dissolve in the acid they dip it in . Lewis then confesses to resurrecting Isaac just to impress Tarby and also because he thought that if the spell worked, he could see his parents again . Feeling betrayed, Jonathan decides he wants to send Lewis away for his disobedience . Lewis runs away crying and Florence tells Jonathan that he is being a coward for trying to avoid responsibility for the boy . Lewis notices Isaac in the house of Jonathan's neighbor Mrs. Hanchett (Colleen Camp). Lewis brings her to the house, but before Lewis can find Jonathan, Isaac emerges . He then reveals that Mrs. Hanchett is really Selena in disguise and that she killed the real Mrs. Hanchett, took her place, and that the key was made from her bones . Selena also reveals that she was taking the form of Mrs. Barnavelt to persuade Lewis into summoning Isaac . Isaac captures Lewis, followed by Jonathan and Florence, where he explains to them after the war, he met a demon named Azazel in The Black Forest who granted him with more power, and reveals that the clock will turn time back so that humanity never existed and uses living puppets and killer pumpkins to send the three away . Jonathan apologizes to Lewis for how he talked to him and they all plan to go back and stop Isaac and Selena . Lewis uses the Magic 8 - Ball to learn the location of the clock under the boiler room . They return to the house, defeat the guardian pumpkins and puppets, and begin searching for the clock . </P> <P> Florence is taken by Jonathan's mutated snake named Snakespeare, leaving Lewis and Jonathan to face the Izzards on their own . Isaac and Selena await as the lunar eclipse is setting, which will activate the clock's power . Lewis and Jonathan try to fight back, but Jonathan is transformed into a baby that still has his adult head . The eclipse begins, and people around town start to de-age to children . Lewis consults the Magic 8 - Ball to know what to do and it says "Say goodbye ." Lewis realizes he has to let go of his pain from losing his parents to harness his true power . He drops the ball into the clock's gears to slow it down, and using his own magic, Lewis blasts Isaac and Selena, causing them to fall, de-age, and ultimately be erased from existence . Everything goes back to normal as Florence reveals that she has fixed Snakespeare and Lewis asks her to be part of his new family . </P> <P> Lewis returns to school with more confidence, and gets revenge on Tarby and his friends by magically bouncing a ball on their faces, and befriends Rose Rita Pottinger . Jonathan then picks him up from school where they go home with Florence as the three of them are now like a regular family, as reflected in the stained glass window . </P> <Ul> <Li> Jack Black as Jonathan Barnavelt, Lewis's uncle and a warlock . </Li> <Li> Cate Blanchett as Florence Zimmerman, Jonathan's neighbor and friend and a witch . </Li> <Li> Owen Vaccaro as Lewis Barnavelt, Jonathan's 10 - year old nephew . </Li> <Li> Kyle MacLachlan as Isaac Izard, an evil warlock </Li> <Li> Renée Elise Goldsberry as Selena Izard, Isaac's wife and a witch . </Li> <Li> Sunny Suljic as Tarby Corrigan, a classmate of Lewis . </Li> <Li> Vanessa Anne Williams as Rose Rita Pottinger, a classmate of Lewis . </Li> <Li> Colleen Camp as Mrs. Hanchett, Jonathan's nosey neighbor . </Li> <Li> Lorenza Izzo as Mrs. Barnavelt, Lewis' mother . </Li> <Li> Eli Roth as Comrade Ivan </Li> </Ul>

What is the movie the house with the clock in the wall about