Lizzie and Alex Brooks are in love and the parents of a little girl, Emma. Without warning, 24-year-old Lizzie suffers a stroke and slips into a deep coma. Alex, determined to observe his vow to love Lizzie in sickness and in health, brings her home and takes care of her. Alex is helped by Lizzie's best friend, Gail, who also cares for Emma. When Gail's husband is killed in a car crash, Alex, Gail and Emma form a family unit of their own. 20 years later, Lizzie wakes up from her coma. Lizzie is pronounced healthy and tries to assimilate back into a changed world. Emma is about to be married and is thrilled to have her mother back, as is Alex and Gail. But Lizzie's presence is also confusing for all of them as she attempts to find her place in their lives.