The story of an estranged father and daughter who, by forces of magic, nature, and fate end up stranded on the same deserted island. Their only hope of escape is to mend their long broken relationship, and experience the values of forgiveness, family, and love.
The father is a world class sailor haunted by what he could have been, and the daughter is a self-deprecating hot mess of a college student. She comes home from school for the summer and finds her father at the Seawanhaka Yacht Club after he misses her birthday dinner. After a nasty argument at the bar, he then departs from the yacht club on his boat....and disappears. Snooping through his office she finds a short story he wrote about a man who sails on his own, gets caught in a storm, and ship wrecked on Sable Island. Feeling a new creative connection to her father and feeling guilty about their argument and worried about him (as his story has no ending yet) she decides to face her fear of sailing and go after him.
In a reenactment of the short story, George gets caught in a storm and knocked out. Meanwhile so does Lizzy as she tries to sail off in a tiny boat she used to learn in as a child. When they awake, the father is stranded on what he presumes might be Sable Island — which is thousands of miles away from Cape Cod, except there are no horses. It would have been impossible for him to arrive there — and then when his daughter arrives he is certain this is not Sable Island but perhaps ... he is dead.
They explore the island, trying to figure out how they ended up there and what it all means, and have many strange and revealing conversations about their relationship. The two are bizarrely visited by Percival Lowell, the famous astronomer who discovered Pluto and a long distant relative of theirs. Finally, Lucy decides to build a raft and get off the island. She doesn't know what's out there but it's better than being stuck on this island. George won't go with her or help build it. Suddenly a change of heart when he sees how hard she is working he helps her. In silence they build together. Lucy assumes this means her father will be leaving with her. But instead he pushes her off. Lucy is confused and devastated. George turns back to the island and there finally is a horse on the horizon. He turns around and runs out into the waves to catch up to his daughter. As he swims he begins to have stroke. Just as he's about to drown Lucy grabs his hand. In a hospital Lucy hesitates before holding her unconscious father's hand. When she does he wakes up looks at her and cries.