While 2024 has been packed with thrilling horror releases, with more still to come, “The Substance” has managed to stand out from the start, receiving an 11-minute standing ovation at the Cannes Film Festival, where it even competed for the Palme d’Or.

The movie centers on Demi Moore’s Elizabeth Sparkle, a once-brilliant star who has faded into oblivion. Desperate to reclaim the spotlight, she is willing to do anything—even inject herself with a mysterious liquid that promises to create a superior version of her persona

Without giving too much away, the title’s ending has become a major talking point, praised as one of the most grotesque, yet fascinating, conclusions of the year. In a conversation with Variety, special effects artist Pierre-Olivier Persin shared all the secrets behind the cathartic finale. (Warning: details about the film’s last 20 minutes ahead.)

‘The Substance’ climax: Pierre-Olivier Persin on designing the chilling end

The first thing Persin revealed was that creating the shocking scenes required an incredible amount of effort, as director Coralie Fargeat insisted on using practical effects wherever possible, instead of relying on digital CGI. As a result, 70-80% of the scenes that shock viewers are achieved with practical effects!

Regarding the monster that takes center stage at the film’s climax, Persin explained that he and his team went through “tons of designs,” using everything from computer-generated models to Photoshop, traditional sculptures, and drawings to create a version that Coralie approved. In the end, Persin sculpted the final form of the creature using a traditional maquette.

The entity, named Monstro Elisasue, initially had puncture holes and multiple spines. As for the obscene amount of blood that sprays the audience during Sue’s New Year’s Eve show, Persin revealed that special effects coordinator Jean Miel built a custom blood rig. “We put that inside the suit and it was like a fireman’s hose that would spray blood”

And if you’re wondering who was inside that monstrous suit, it was none other than Margaret Qualley! Persin shared that it was no easy task for her, as she had to wear a cooling vest, similar to what race car drivers use. “It had a cooling system that would inject cold water to cool her down,” he explained.