At a sanatorium in the Adirondacks, a young tutor falls in love with a mysterious woman suffering from tuberculosis who survived the Lusitania disaster.

Recently jilted by his fiancée, Paul Gascoyne takes a job as a tutor to the patients at the Trudeau Sanatorium in upstate New York. There, in the icebound beauty of the Adirondack Mountains, he finds himself drawn to Sarah Ballard, a beautiful but enigmatic young woman, traumatized by her past aboard the ill-fated Lusitania. To rouse her out of her gloom, Paul encourages her to write a memoir.

As Paul reads her words, it gradually becomes clear that Sarah's memories are a tangle of truth and fiction that he can't begin to unravel. And yet he cannot overcome his attraction to her. When a terrible relapse leaves her worried that she has little time left, Sarah begs Paul to be the one person in the world who will truly know her.