The Substance's tight focus on its central cast benefits the dark horror satire about the entertainment industry. Written and directed by Coralie Fargeat, The Substance is focused on an aging actor celebrity who finds herself without a job after being forced out of her TV show. Desperate to regain her notoriety, she reluctantly starts using a mysterious black market drug that creates a second younger version of herself. The Substance is largely focused on the back-and-forth that erupts between the two versions of the celebrity, steadily exposing their internal fears and darker impulses.

The film maintains its focus primarily on its lead character, Elisabeth. An aging star who fears her golden days are behind her, Elisabeth decision to embrace the Substance as a solution to her problems only sets her up for far more horrifying results. The main cast of the body horror film The Substance is limited to only three actors,...