The Substance

Elisabeth Sparkle is a once-beloved celebrity who hosts a popular TV fitness show. On her fiftieth birthday she is dropped by her sleazy producer Harvey, who replaces her with someone younger. Devastated and desperate, she obtains a black-market substance: an injection that will create a stabilized, younger version of herself.

The substance splits Elisabeth's body open and Sue emerges from her spine — younger, more perfect, everything Elisabeth wanted to be. The rules are strict: they alternate every seven days, and whatever one does to their shared body the other will experience. Elisabeth lies dormant while Sue lives, and vice versa.

Sue becomes an immediate sensation — the new star of the fitness show, adored by audiences and the industry. Elisabeth, during her turns, grows consumed by jealousy and self-loathing, watching as her younger self thrives. She begins violating the seven-day rule, extending her time as Sue and compressing her time as Elisabeth. Her original body begins to deteriorate — hair falling out, skin sagging, one eye sinking.

Sue, aware that Elisabeth is shortening her turns, begins doing the same, trying to become permanent. When both are active simultaneously they violently confront each other. Elisabeth, desperate to repair her deteriorating body, drains Sue's cerebrospinal fluid to fill in her own decaying flesh.

The two bodies wage war on each other. Sue attempts to keep Elisabeth permanently dormant and broken. Elisabeth, in a moment of furious self-assertion, refuses to disappear. They tear into each other and in the film's climactic act, their bodies fuse grotesquely into a single entity — Monstro Elisasue, a lurching, writhing amalgamation of both women.

The creature crashes the televised New Year's Eve celebration on which Sue was meant to appear triumphant. It lurches across the stage as the crowd watches in horror, then disgust, then violence — throwing objects, attacking it. The monster is destroyed, bombarded by the crowd and the industry that created both women. It dissolves. The film ends in silence, on a star on the Hollywood Walk of Fame with Elisabeth Sparkle's name, cracked down the middle.