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There are plenty of reasons why writer-director Ari Aster’s family-drama-cum-horror movie Hereditary has unnerved film festival audiences. Chief among them? The performance of actress Milly Shapiro (of Broadway’s Matilda) as the central clan’s strange, toy-making daughter, Charlie.

“I think Milly Shapiro is a genius,” says Alex Wolff, who play’s Charlie’s older brother, Peter. “She’s just a fantastic person and a fantastic actress. I was learning from her every day. I don’t want to give too much away, but she doesn’t talk much in the movie, [and] the director, Ari, had us go out to lunch as the characters. So we would go out on these silent long walks, and we would hold hands while we went up the street, but we wouldn’t say a word to each other. We’d go out to lunch, and I would try and get to her to tell me what she wanted to eat, and she wouldn’t do it, which really got us linked in the way that the characters are linked.”

Costarring Toni Collette, Gabriel Byrne, and Ann Dowd, Hereditary hits theaters June 8. You can see the film’s new, Charlie-showcasing trailer above, and you can even buy Charlie’s disturbing crafts on Etsy.