This novel follows the protagonist, a renowned Harvard psychologist named Alice Howland, shortly before she is diagnosed with early-onset Alzheimer's disease The protagonist, Alice, is successful and ambitious but everything falls apart when she gets Alzheimer's disease. Each chapter is a month from 2003 - 2005.
Alice is invited to Stanford's follow series speakers conference and she notices that she couldn't remember simple words during her presentation. She then flies to Los Angeles to meet her youngest daughter, Lydia. Both women bicker constantly because Alice wants Lydia to go to college or university instead of pursuing an acting career. Lydia notices Alice is becoming forgetful.
Alice returns home to Cambridge and finds that her husband who is a scientist, John, is still working on his experiments at Harvard. She decides to go for a run and forgets the way home. Eventually she remembers and when she gets home, she researches the symptoms of menopause. She decides to make an appointment with a doctor.
Then, Alice has a birthday celebration with her older children, Anna and Tom, and son-in-law, Charlie. After, Alice has her appointment with Dr. Moyer. At the end of the assessment, Dr. Moyer requests an MRI for Alice.
Afterwards, Alice returns to work and can't remember what she is supposed to be teaching. At the end of the day, John asks why she is still in Cambridge because she was supposed to attend a conference in Chicago. Alice requests see a neurologist on her second doctor's appointment.
Alice and John attend a Christmas party hosted by Alice's colleague. She meets her graduate student's wife but forgets her after 10 minutes, making John and Dan feel awkward.
Prior to Christmas, Alice visits Dr. Davis, a neurologist. After an assessment, Dr. Davis needs time before a diagnosis could be given. By Christmas Eve, Alice has trouble remembering Lydia. She also becomes frustrated when she can't make the usual dessert and creates a mess in the kitchen.
On January 19th, a day considered bad luck because Alice's mother and sister, Anna, died in a car accident years ago on the date, she is diagnosed by Dr. Davis with early-onset Alzheimer's disease. She is also told to bring another person on her next visit. Alice struggles to come to terms with it and reviews the questionnaire Dr Davis gives her at home. After, John and Alice make a trip to the cemetery to visit Alice's family.
She concludes her dad might have had it and becomes more resentful towards him since he was an alcoholic. 10 days later, Alice tells John about diagnosis and he refuses to believe it. He wants to talk to the neurologist after doing some research about the disease. After John completes research, they visit a genetic counselor named Stephanie Aaron. John wants her to screen Alice for mutations linked to Alzheimer's to confirm whether or not she truly has it.
Later, it's confirmed that Alice has these mutations. John and Alice decide to tell the children and on the way home from the appointment, John cries. They tell their children and Anna and Tom want to check for mutations. Anna is distraught because she doesn't want her future children to get it since she's been trying to get pregnant. Lydia doesn't want to get checked.
A fews days later, Anna and Tom are checked and only Anna has the mutations. Alice visits a Nursing centre for Alzheimer's patients and doesn't think she belongs there. She types a set of questions on her Blackberry for self-assessment and writes a note on the computer in case she can't answer the questions.
She and John go to the neurologist and Alice admits she went to the office thinking it was day. John discusses different medications and Alice wants to use a trial drug.
John and Alice go on vacation and on one of the days, Alice has a break down because she doesn't remember where the washroom is. John is supportive. They return and John has a conference to attend so Lydia takes care of Alice. Alice forgets her family has died. Lydia and Alice bond after she explains why it is important for Lydia to attend post secondary.
In the evening, she reads Lydia's diary and she becomes angry. Later, Lydia puts it on Alice's pillow for her to read. Anna and Tom visit and don't understand the disease at an emotional level. Later, everyone attends Lydia's play and Alice forgets who Lydia is.
In September 2004, Alice has a meeting with the department head, Eric. He tells her about the abnormal bad rating of her teaching and she tells him about her condition. They discuss her career and Eric thinks Alice needs to phase out slowly. She sends a message to her co-workers and they become awkward around her.
As the days go by, Alice has more moments and one day thinks that her neihhbour's kitchen is her own. Anna finally becomes pregnant through in-vitro. For Alice's birthday, her kids compile a video of her life as a gift. Then Alice begins a support group for other pat