Dr Abby DiMatteo - a second-year surgical student in Boston Bayside's elite cardiac team - is about to make a decision that will jeopardize her career.

A car-crash victim's healthy heart is ready to be harvested, having been cross-matched to a private patient, forty-six year-old Nina Voss. Instead Abby makes sure the transplant goes to a dying seventeen-year-old boy who is also a perfect match.

The repercussions leave her plagued with self-doubt. Suddenly a new heart appears, and the transplant is completed - but Abby makes a terrible discovery. The new heart has not come through the right channels.

Defying the hospital's demands for silence, Abby begins her own investigation that reveals an intricate and murderous chain of deceptions ...