Novelist J.B. Blackwood is on a cruise with her husband, Patrick, to celebrate their wedding anniversary. Patrick is older than J.B., a revered film director and formerly her professor. J.B's art has been forever overseen by him, now it may overshadow his.

For days they sail in the sun, with nothing but dark water all around them. Then a storm hits, and Patrick falls off the ship.

J.B. is left alone, as the search for what happened to Patrick - and the truth about their marriage - begins.