Natasha Calis' behavior is a little erratic in this new clip from The Possession. Check it out:

Calis stars as Em, a girl who becomes possessed after buying a box from a garage sale that allegedly contains a Dibbuk, an ancient demon from Jewish folklore. The possession goes largely unnoticed by her recently-divorced parents, played by Jeffrey Dean Morgan and Kyra Sedgwick, until her behavior gets extreme.

Sam Raimi, whose new film Oz: The Great and Powerful comes out next year, produced the film. Ole Bornedal directs.

The Possession will hit theaters August 31. For more, watch The Possession trailer.