When Mitt and Ann Romney met in their late teens, a great American love story began. And their life together would be blessed: five healthy sons, financial security and a home filled with joy. Despite the typical ups and downs, they had a storybook life.

Then, in 1998, Ann was diagnosed with multiple sclerosis. She couldn't believe it was real; there were no therapies or treatments to help her. Mitt told her that day that they would tackle the diagnosis as a team: They were in it together. "As long as it isn't fatal, we're fine. If you have to be in a wheelchair, I'll be right there to push it," he told her. And Ann thought, "But I'll be the one in the wheelchair." A caregiver and helper her whole life, she'd crossed a terrible invisible line. She wouldn't be able to care for her family anymore. She was the patient. Ann and Mitt would face the most frightening and humbling experience of their lives.