The story opens when a United States Coast Guard helicopter, responding to a distress signal, discovers a disabled sailboat in a storm on the Gulf of Maine. Aboard are an injured man, Tom O'Connor, and his granddaughter, Rachel.

Tom is a retired lawyer who opted out of society to cruise to Europe with Anna, his wife and childhood sweetheart, in their sailboat, nicknamed "Annie." When his wife dies, Tom's grief is inconsolable. He becomes a recluse, wandering the Atlantic coast and following the seasons from Nova Scotia to the Florida keys. His boat assumes aspects of the persona of his dead wife, who returns to share his lonely existence as a ghost of his imagination.

The tragic death of his daughter in an automobile accident leads Tom to kidnap his granddaughter Rachel. Together, they sail Annie to Nova Scotia during a summer on the lam from the authorities.

During this odyssey, which culminates in the storm that disables Annie and threatens Tom's life, he and his granddaughter establish an insightful relationship which helps resolve their respective despondency and leads to fulfilment based on mutual interdependence and love.