The Substance stars Moore as a TV fitness guru named Elisabeth Sparkle whose boss ( Dennis Quaid) wants to replace her with someone younger—so she uses a mysterious black-market drug to create a more youthful version of herself, who goes by Sue (Qualley). If you've not yet seen it in a theater, it heads to streaming on Mubi on Oct. 31.

Demi Moore had quite the Halloween surprise for fans of The Substance. In celebration of her horror film becoming able to stream on MUBI, the actress decided to share four shocking behind-the-scenes photos from the set of her latest critically acclaimed movie.