Anne, a high-strung, game show fanatic, receives distressing news that her mother, who has a serious gambling problem, has fled to Macau. This shocking revelation brings her back together with her estranged, reckless older sister, Jenny Yum, who has been living in her car but is now temporarily staying with Anne. One evening, while Anne is engrossed in her beloved game show, Can't Stop the Quiz, Jenny seizes the opportunity to record Anne showcasing her impressive trivia skills and then uploads the clip online, where it ignites a viral sensation.
However, this unexpected fame draws the attention of a dangerous loan shark, to whom their mother owes a staggering $80,000. The loan shark tracks down Anne and demands she pay off her mother's debts, even going so far as to kidnap her pet dog, Mr. Linguini, as leverage. In a desperate turn of events, Anne confronts Jenny, blaming her for the situation, and pleads for her to utilize the money from a recent lawsuit against a restaurant chain to help retrieve Mr. Linguini. To Anne's dismay, Jenny confesses she lied about winning the lawsuit and is unable to assist. Instead, she encourages Anne—fresh off her viral fame and with interest from the Can't Stop the Quiz casting directors—to appear on the show to potentially win enough money to secure her dog's return.
As Anne prepares for her audition, a mishap occurs when Jenny dislocates her wrist at a bar. While at the hospital reminiscing about their childhood, Anne reveals an embarrassing story involving defecation at a cousin's house during a summer stay, due to feeling unwelcome. Jenny reassures her, stating that their cousins always had issues with their branch of the family, which explains why they were never welcomed back. On audition day, Anne's anxiety gets the best of her, and she considers leaving before it starts. However, Jenny gives her calming pills that unwittingly turn out to be hallucinogenic. With the help of other medication to counter the effects, Anne ultimately wowed the audience and producers with her performance.
The following morning, amid jubilation, Jenny reveals that the entire situation was part of her elaborate scheme to become a self-styled life coach. She claims to have genuinely won a hefty settlement from her lawsuit and manipulated events to ensure Anne's participation on the quiz show since she believed her sister wouldn't do it otherwise. This revelation infuriates Anne, who feels betrayed. Yet, in a surprising twist, Jenny recalls the moment Anne's childhood indiscretion was exposed, highlighting how she had covered for her, saying it was Jenny who did it, resulting in their family being disinvited from future visits.
After returning home, Anne finds solace in an unexpected invitation from her cantankerous neighbor, Francine, who offers her a cup of tea and wisdom about the futility of seeking validation from others. Shortly after, Anne receives a call that she has been invited to participate in Can't Stop the Quiz, deciding to team up with Francine. Meanwhile, Jenny, determined to get Mr. Linguini back, cleverly negotiates with the loan sharks and successfully retrieves the dog.
When Anne competes in the show, she faces off against Ron, the reigning champ, finishing the first round in a disappointing second place. However, Jenny arrives with Mr. Linguini, persuading Anne to continue the game with her at her side. During an emotional charades round, Anne expresses to Jenny that she sees her as a hero, strengthening their bond. Ultimately, Anne emerges victorious, setting a stunning record by winning 93 consecutive games and securing a writer’s position on the show.
With Jenny’s lawsuit settlement finally arriving, the sisters manage to clear their mother’s debts and even splurge on a luxurious Malibu mansion where they can start anew together.
