Lucy Houston and Mickey Chandler probably shouldn't have fallen in love, let alone gotten married. They're both plagued with faulty genes-he has bipolar disorder; she, a ravaging family history of breast cancer. But when their paths cross on the night of Lucy's twenty-first birthday, sparks fly, and there's no denying their chemistry. Cautious every step of the way, they are determined to make their relationship work-and they put their commitment in writing. Mickey will take his medication. Lucy won't blame him for what is beyond his control. He promises honesty. She promises patience. Like any marriage, there are good days and bad days-and some very bad days...