Angela Rippon investigates the disease that took her mother's life and is now starting to affect her friends. She undergoes a series of tests to discover if she has any early signs of the disease and makes the difficult decision about whether to take a genetic test that could predict her future risk. Along the way, Angela finds out some of the surprising ways people can help to protect themselves. She discovers why getting a good night's sleep could help prevent Alzheimer's and how learning a new language might be more effective than any current drug treatment. Angela also visits a number of people who are living with the disease, including Bob, the husband of one of her oldest friends. She meets families that carry a gene for early-onset Alzheimer's and discovers how they could be the best hope of finding a cure for this devastating disease.