The Substance, Coralie Fargeat’s outrageous new body-horror movie, ends the only way it can: in a great, explosive bloodbath. It’s a fantastic premise based on Fargeat’s very real fears.

“The idea came from living in my own life as being a woman past my 40s, going toward my 50s,” Fargeat tells Inverse. “I started to have those very violent thoughts that it was going to be the end of my life because I wouldn't be able to be valued as a young, sexy girl.”

“Have you ever dreamt of a better version of yourself?” reads the cooly seductive tagline for the Substance, the mysterious illicit drug that is offered to aging aerobics star Elisabeth Sparkles (Demi Moore). It’s a tantalizing promise, but a false one: the Substance only creates a younger double (played by a doe-eyed Margaret Qualley) that Elisabeth births from her own spine — a double that lives out the fabulous life of fame and fortune Elisabeth yearned for, while draining Elisabeth’s life force.

Inverse spoke with Fargeat about casting Demi Moore in the performance of a lifetime, her greatest body-horror inspirations, and that jaw-dropping, terrifically gory final act.

Years before she made The Babadook, Jennifer Kent had already lived through its scariest scene.

“The bug thing came from an experience I had when I was in acting school,” the Australian filmmaker tells Inverse. “All these cockroaches behind the fridge would appear in this little crack in the wallpaper. And so one day I peeled it back and it was just” — Kent shudders and trails off as the memory overtakes her — “I can't describe how revolting that was.”

If you haven’t seen The Babadook since its 2014 release (or, more likely, since it went viral on Netflix in 2017) you may have memory-holed this particularly disturbing moment in a movie full of them. Widowed mother Amelia Vanek (Essie Davis) is already struggling to raise her young, behaviorally challenged son Samuel (Noah Wiseman) when they suddenly become haunted by a demonic presence called the Babadook. The creature first appears in a disturbing pop-up book that traumatizes Noah, before possessing Amelia directly, giving her visions of cockroach infestations and ultimately goading her to murder her own son and pet dog.

The movie landed quietly at Sundance back in 2014 but found a home on Netflix. The Babadook became a cultural phenomenon (and somehow, a gay icon) even as Kent refused various requests to make sequels, spinoffs, and adaptations. Now, a decade later, she’s taking a victory lap.