It's Alice's birthday, and she's celebrating her 50th at a chic restaurant alongside her husband, John and their children. Sadly, her daughter Lydia, portrayed by Kristen Stewart, is unable to attend due to an audition. Alice, a distinguished linguist, is eagerly awaiting her guest speaker role in a UCLA class, where she plans to discuss the intricacies of how babies acquire language and understand irregular verbs. However, during her talk, a surprising moment strikes—she suddenly loses her train of thought.
After this incident, Alice engages in a game of Words with Friends in the car before visiting Lydia for dinner. Their conversation revolves around Lydia's aspirations in acting, something Alice wishes her daughter would reconsider in favor of pursuing a college education. The evening concludes with Alice returning to an empty home in NYC, prompting her to go for a jog. Unfortunately, during her run, she forgets her surroundings, which distresses her. She eventually regains her bearings but finds herself troubled upon discovering that John is financially supporting Lydia's theater endeavors.
Concerned about her memory lapses, Alice consults a doctor, who administers various memory exercises. While she performs well in most tasks, one test troubles her, leading her to fear she might have a brain tumor. A precautionary MRI is scheduled, and Alice finds herself preparing Christmas dinner, attempting to engage in memorization exercises. However, her memory fails her repeatedly, and she experiences embarrassing moments, like reintroducing herself to her son's girlfriend, Jenny.
When the MRI yields no alarming results, the doctor recommends a PET scan to check for early-onset Alzheimer's. Alice's anxiety escalates as she breaks the news to John, whose denial leaves her feeling isolated and overwhelmed. The grim diagnosis soon follows, testing Alice and her children for the genetic marker linked to the disease. Her eldest daughter, Anna, discovers she's a carrier, but finds some solace in knowing that they can screen embryos for the gene during her fertility treatments.
Caught in an emotional battle, Alice confronts criticism from her students, who share unflattering reviews about her course. Despite her struggles, she expresses a desire to remain in her position for as long as possible. One evening, after a solo visit to Pink Berry for yogurt, she forgets about significant dinner plans with John, who becomes upset with her.
As the narrative unfolds, Alice visits a nursing home under the guise of checking on her parents, while secretly taking notes and making distressing recordings for herself—videos outlining her declining mental state and plans for a future she fears she won't remember. Overwhelmed by her condition, she wears a bracelet labeled "memory impaired" and faces the harsh reality of losing her position at Columbia.
As Alice’s memory further deteriorates, she struggles with everyday tasks, even failing to recognize her own family members. When John receives a job offer at the Mayo Clinic, tensions rise as she begs him to postpone the opportunity, fearing being left alone in her gradual decline. With mounting despair, she frantically searches for her phone, only to discover it hidden in the freezer, revealing how disconnected she has become from time.
Amidst all this, their daughter Anna gives birth to twins, but John hesitates to let Alice hold them, fearing she may not recall who they are. With the introduction of a caregiver named Elena, Alice is reminded of her fragility when left alone, leading her to revisit recordings where she contemplated taking her own life. During a harrowing moment, just as she attempts to follow through with her own instructions, Elena arrives, unknowingly saving her from that fate.
In the final act, as John and Alice indulge in frozen yogurt, Alice struggles with simple choices and her memories fade concerning her former life. With Lydia returning home to assist, a poignant scene unfolds as Lydia reads to her. In a fleeting moment of clarity, Alice reflects on love and happiness—a final embrace of the life she once knew, leaving viewers with the heart-wrenching realization of her ongoing struggle with Alzheimer’s.
