Act I
The show opens with Viola Van Horn and her group of immortals sharing "a secret you would die for" by offering the audience a magic potion that grants eternal beauty and perfection ("If You Want Perfection").
Vain and self-absorbed actress Madeline Ashton performs in the Broadway show Me! Me! Me! ("For the Gaze"). She is visited by her old friend and struggling writer Helen Sharp, whom she frequently belittles and insults for her own amusement. However, Helen has one-upped Madeline by revealing she is engaged to famed plastic surgeon, Ernest Menville, and relishes the opportunity to get back at her frenemy ("That Was Then, This is Now").
Madeline invites the two over to her home, where she seduces Ernest ("Tell Me, Ernest"), steals him from Helen and ends up marrying him ("Madeline Ashton's Intimate Wedding Extravaganza"), with Ernest promising during the wedding to stay "til death do us part" ("Ernest's Real Vows"). Helen, meanwhile, is sent to a psychiatric hospital, where she obsesses over killing Madeline ("Madeline").
Ten years later, Madeline and Ernest are still unhappily married. Madeline has begun to age visibly, costing her acting jobs ("(I See) Me!"). Ernest, now a plastic surgeon in Hollywood, copes with his regret by drinking ("Til Death"). The couple are invited to Helen's first book publication, where they find Helen has become young, successful, and beautiful. At the party, Madeline is given the business card of Viola Van Horn by her mysterious assistant, Chagall. Helen openly flirts with Ernest and further humiliates Madeline by mocking her age and her recent embarrassing movie roles ("Tell Me, Ernest (Reprise)"). Madeline has a panic attack in the parking lot and vows not to let her career and image "fall apart" before she visits Viola at her home ("Falling Apart").
Viola offers Madeline the potion on the condition that she vanish from the public eye after ten years to keep its existence a secret. She takes the potion, becoming young and beautiful again. Viola leaves Madeline with a warning: "take care of your body" ("Siempre Viva").
Back at Ernest and Madeline's home, Helen breaks in and rekindles her relationship with Ernest, and the two plan to run away together by murdering Madeline ("Let's Run Away Together"). Upon Madeline's return, she and Helen get into a fight, which results in Madeline falling down the stairs and breaking her neck. As Helen comes up with a new plan to report Madeline's death as an accident, Madeline reanimates, accusing Helen of pushing her intentionally ("Confrontation").
Act II
Viola returns to the stage to address the audience and to admonish Madeline for ignoring her warning ("Don't Say I Didn't (Warn You)").
Ernest frantically drives Madeline to the hospital, where it is confirmed that she is clinically dead, yet still alive. Returning home, Madeline realizes Helen has taken the potion as well and shoots her with a shotgun, leaving a massive hole in her torso. Their bickering leads to further violence and more injuries: Helen is impaled by an umbrella, and Madeline is decapitated before Ernest stops them ("Hit Me"). The two women coerce Ernest to use his surgical skills to repair their bodies, and he agrees on the condition that he be allowed to leave afterward. Drunk and delirious, Ernest plans to fix them with glue, clay, and spray paint ("The Plan"). He also fires Stefan, Madeline's long-suffering assistant, to prevent him from discovering the secret ("Stefan's Turn").
Madeline and Helen realize they'll need Ernest for maintenance and plot to drug him and have him drink the potion so he can become immortal too. After knocking Ernest out, they take him to Viola's, where she is hosting a ball with the other immortals ("Live to Serve"). Ernest awakens, and Viola tempts him with the potion, but he rejects it and tries to flee the house with it ("Siempre Viva (Reprise)"/"The Chase"). He is chased to the roof, where he says he would rather die than spend eternity with Madeline and Helen, before he is pushed to his apparent death by Viola ("Til Death (Reprise)").
Helen despondently realizes she's doomed to outlive all of her friends and family and be alone forever. Madeline, finally apologizing for her actions, tells her that they can fix one another and can be each other's "person" ("Alive Forever"). The two drop their rivalry, embrace, and head home.
Fifty years later, Madeline and Helen visit their graves to maintain them. They run into an elderly Ernest, who had survived the fall, fell in love with his nurse, married her, and had children and grandchildren. As Ernest and his wife leave, Helen and Madeline momentarily lament that they will never have an "ending" of their own before exiting the cemetery together ("The End").
