A young woman in London faces the prospect of a deadly thank you in return for an act of selfless generosity. She is Mary Jago who donates her bone marrow to save the life of a man she does not know. As her grandmother puts it, some people dislike those who have done them a service.

In a small Northern Italian village, nine-year-old Luca Taviano catches a stubborn cold and is subsequently diagnosed with leukemia. His only hope for survival is a bone marrow transplant. After an exhaustive search, a match turns up three thousand miles away in the form of a most unlikely donor: Joseph Neiman, a rabbi in Brooklyn, New York, who is suffering from a debilitating crisis of faith. As Luca's young nurse, Nina Vocelli, risks her career...