Because he can't reach the hospital in a winter snowstorm, Dr. David Henry ends up assisting his own wife in the birth of their twin children at his clinic with the help of his nurse, Caroline. The boy is fine; the girl has Down symdrome. While his wife is as yet unaware, he gives the girl baby to Caroline to take to an institution. Norah, his wife, remains unaware that she give birth to two children, yet is haunted by some sense of loss she can't name. Caroline, unable to leave the baby in an unappealing institutional setting, makes a snap decision to keep her. She leaves town, renewing communication later with the baby's father, and raises her as a single mother until she meets a man who is willing to marry her and love Phoebe as a daughter.

Only after Dr. Henry dies suddenly does his wife discover the existence of her daughter, through photographs sent to him over the years by Caroline, and then a visit from Caroline and Phoebe. Sadly, but with a will to choose life on strange and demanding terms, Norah and her son, Phoebe's brother, choose to enlarge their circle of family to include a loving relationship with Phoebe, clearly her own person, and the woman and man who have cared for her.