Diane McGowan (Mia Farrow) was an attorney in a private law firm.
When she found herself forgetting things, especially things that have just happened she didn't think much of it.
However she suspected that something was wrong and went to the doctor. After many tests the diagnosis was Alzheimer's disease.
Diana did not want to tell her husband, Jack McGowin (Martin Sheen) because she thought her husband, Jack, would be worried about money since she made more money than he did and therefore unwantingly burdoning him so she decided to keep her condition a secret from him.
Yet, when she had to give a speech at a political party meeting, she got really confused and had no idea of where she was. Diana called her house by reading her cheque book and by her son recognizing her voice.
She was then forced to tell her family: her husband Jack, her daughter Kate, and her son that she had Alzheimer's which they had known to a certain degree.
Later she befriends an ex-professor college professor, Dr. Albert Morelli (Colm Feore), who also has the illness and they began to do things together. His illness was much more advanced than hers. She can learn where she is heading. Paula Morelli, Albert's sister had to put him in a nursing home. Diana started a therapy group with people who shared the same illness.