When Lewis Barnavelt (Owen Vaccaro) is orphaned, he goes to live with his mysterious uncle, Jonathan Barnavelt (Jack Black). Lewis finds to his surprise that Jonathan is a warlock. The house where Jonathan lives was once owned by a couple who were dedicated to black magic. Before they passed away, they hid a clock in the walls with the power to bring about the end of the world.
Lewis and Jonathan have to find the clock before it's too late.