section_path: Plot
section_name: Plot
paragraph_text: Plot
  
  On her 50th birthday, Elisabeth Sparkle, a once-celebrated but now-faded Hollywood film star, is abruptly dismissed from her long-running aerobics TV show by Harvey, the producer, due to her age. A distraught Elisabeth crashes her car while distracted by a billboard of herself being taken down. At the hospital, a young nurse covertly gives her a flash drive advertising "The Substance", a black market drug that promises a "younger, more beautiful, more perfect" version of oneself.
  
  Elisabeth, intrigued and desperate, orders The Substance and injects the single-use activator serum. She convulses as her body generates a younger woman, Sue, emerging from a slit in her back. The two bodies must switch consciousness every seven days without exception, with the inactive body remaining unconscious and fed intravenously with a weekly food supply. Daily injections of stabilizer fluid, extracted from the original body, are required to prevent the new body from deteriorating.
  
  Sue becomes an overnight sensation after auditioning to be Elisabeth's replacement and is eventually offered the chance by Harvey to host the network's prestigious New Year's Eve show. While Sue lives a confident and hedonistic life, Elisabeth becomes a self-hating recluse. Near the end of one weekly cycle, Sue brings a man home for casual sex; she delays the switch by extracting additional stabilizer fluid, causing Elisabeth's right index finger to rapidly age. Elisabeth contacts the supplier, who warns her that disobeying the switching program will lead to irreversible, rapid aging of the original body.
  
  Elisabeth begins to resent Sue for her disregard of the switching schedule, while Sue starts resenting Elisabeth for her self-loathing and binge-eating. Following a particularly destructive episode as Elisabeth, Sue stockpiles stabilizer fluid and refuses to switch back.
  
  Three months later, on the day before the New Year's Eve telecast, Sue runs out of stabilizer fluid and contacts the supplier, who informs her that she must switch back to replenish the fluid. When they switch, Elisabeth finds herself transformed into an elderly deformed hunchback. Desperate to stop Sue from aging her further, Elisabeth orders a serum designed to terminate her. However, Elisabeth, still craving the admiration that Sue's celebrity status provides, stops before fully injecting the serum and resuscitates Sue, leaving both of them conscious. Realizing Elisabeth's initial intent, Sue attacks and kills Elisabeth before leaving to host the New Year's special.
  
  Without Elisabeth, Sue's body begins to rapidly deteriorate. In a panic, she attempts to create a new version of herself using the leftover activator serum, despite the single-use warning. This results in the creation of a grotesque mutated body, "Monstro Elisasue", with both Elisabeth and Sue's faces. Wearing a mask cut from a poster of Elisabeth, Monstro Elisasue returns to the studio and attempts to host the show, but the audience erupts into chaos. An audience member decapitates her, only for an even more mutated head to grow back, and one of her arms to break and drench both the audience and studio in blood.
  
  Monstro Elisasue flees the studio but collapses and explodes into viscera. Elisabeth's original face detaches from the gore, crawling onto her neglected star on the Hollywood Walk of Fame. She smiles as she hallucinates being admired before melting into a puddle of blood, which is cleaned up by a floor scrubber the next day.
  
  On her 50th birthday, Elisabeth Sparkle, a once-celebrated but now-faded Hollywood film star, is abruptly dismissed from her long-running aerobics TV show by Harvey, the producer, due to her age. A distraught Elisabeth crashes her car while distracted by a billboard of herself being taken down. At the hospital, a young nurse covertly gives her a flash drive advertising "The Substance", a black market drug that promises a "younger, more beautiful, more perfect" version of oneself.
  
  Elisabeth, intrigued and desperate, orders The Substance and injects the single-use activator serum. She convulses as her body generates a younger woman, Sue, emerging from a slit in her back. The two bodies must switch consciousness every seven days without exception, with the inactive body remaining unconscious and fed intravenously with a weekly food supply. Daily injections of stabilizer fluid, extracted from the original body, are required to prevent the new body from deteriorating.
  
  Sue becomes an overnight sensation after auditioning to be Elisabeth's replacement and is eventually offered the chance by Harvey to host the network's prestigious New Year's Eve show. While Sue lives a confident and hedonistic life, Elisabeth becomes a self-hating recluse. Near the end of one weekly cycle, Sue brings a man home for casual sex; she delays the switch by extracting additional stabilizer fluid, causing Elisabeth's right index finger to rapidly age. Elisabeth contacts the supplier, who warns her that disobeying the switching program will lead to irreversible, rapid aging of the original body.
  
  Elisabeth begins to resent Sue for her disregard of the switching schedule, while Sue starts resenting Elisabeth for her self-loathing and binge-eating. Following a particularly destructive episode as Elisabeth, Sue stockpiles stabilizer fluid and refuses to switch back.
  
  Three months later, on the day before the New Year's Eve telecast, Sue runs out of stabilizer fluid and contacts the supplier, who informs her that she must switch back to replenish the fluid. When they switch, Elisabeth finds herself transformed into an elderly deformed hunchback. Desperate to stop Sue from aging her further, Elisabeth orders a serum designed to terminate her. However, Elisabeth, still craving the admiration that Sue's celebrity status provides, stops before fully injecting the serum and resuscitates Sue, leaving both of them conscious. Realizing Elisabeth's initial intent, Sue attacks and kills Elisabeth before leaving to host the New Year's special.
  
  Without Elisabeth, Sue's body begins to rapidly deteriorate. In a panic, she attempts to create a new version of herself using the leftover activator serum, despite the single-use warning. This results in the creation of a grotesque mutated body, "Monstro Elisasue", with both Elisabeth and Sue's faces. Wearing a mask cut from a poster of Elisabeth, Monstro Elisasue returns to the studio and attempts to host the show, but the audience erupts into chaos. An audience member decapitates her, only for an even more mutated head to grow back, and one of her arms to break and drench both the audience and studio in blood.
  
  Monstro Elisasue flees the studio but collapses and explodes into viscera. Elisabeth's original face detaches from the gore, crawling onto her neglected star on the Hollywood Walk of Fame. She smiles as she hallucinates being admired before melting into a puddle of blood, which is cleaned up by a floor scrubber the next day.