That's the question asked repeatedly in the first trailer for gothic horror film The House With a Clock in its Walls.
Starring Jack Black as Jonathan Barnavel - a warlock and uncle of newly orphaned 10-year-old Lewis Barnavelt, sent to live with Black in the titular house - and Cate Blanchett, Barnavelt's neighbour and witch, Florence Zimmermann things are certainly mysterious.
Especially when you've got your uncle saying things like "This house is a very old place. There's a clock in the walls. We don't know what it does, except... something horrible," and you somehow manage to wake the dead.
Directed by Eli Roth, the film also stars Kyle MacLachlan, Colleen Camp, Renee Elise Goldsberry, Vanessa Anne Williams, and Sunny Suljic and is adapted from John Bellairs' 1973 novel by Eric Kripke. Owen Vaccaro plays Lewis.
It's set for a September US release date (Australia TBC).