In the new movie Colossal (out April 7, and just announced as part of the lineup for South by Southwest), Anne Hathaway already has enough on her plate to deal with — including a breakup and a humbling return to her hometown — before she discovers one last, fairly significant thing: She’s also a monster. Or, to be more specific, Hathaway can inadvertently manifest a monster simply by stumbling across a children’s sandbox near her home, at which point this gigantic Groot-beast will appear in South Korea, mimicking her every moment. But how do you prove a power this far-fetched to a group of skeptical friends, including Jason Sudeikis and Tim Blake Nelson? Simple: You dance. Below, use a special slider to switch between Hathaway’s I’ll-prove-it-to-you boogie and the Hatha-monster’s replicated dance moves a continent away, and marvel that a movie could contain something this delightfully odd, as well as much, much more.