Jane Margaux is a lonely child who feels neglected by her parents. To cope, she creates an imaginary friend named Michael, who spends time with her every Sunday in New York.
When Jane grows up, Michael disappears, as imaginary friends are supposed to. Years later, as an adult, Jane unexpectedly sees him again—but this time, he is real.
They fall in love, but their relationship is complicated by secrets from the past and Michael’s mysterious role in Jane’s life.