On the surface, Maud and Tim seem ill-matched. Maud is a scientist, an only child from a modest background; Tim is a musician from a large, rich family. She is emotionally cool, he wears his heart on his sleeve. Yet they make a home together, have a child and restore an old yacht. One day they will sail it, all three. But when a dreadful tragedy occurs, Maud appears strangely unscathed. Tim's family are horrified - what is wrong with her? She tells no one when she begins to feel a ghostly presence, or of her plan to sail single-handed across the Atlantic. Maybe this way she can escape what is pursuing her.