Harvest by Tess Gerritsen

Medical resident Dr. Abby Matteo is elated when the elite cardiac transplant team at Boston's Bayside Hospital taps her as a potential recruit. But faced with a tormenting life-and-death decision, Abby helps direct a crash victim's harvested heart to a dying teenager -- instead of the wealthy older woman who was supposed to receive it.

The repercussions leave Abby shaken and plagued with self-doubt.

Suddenly, a new heart appears, and the woman's transplant is completed. Then Abby makes a terrible discovery. The donor records have been falsified -- the new heart has not come through the proper channels. Defying the hospital's demands for silence, she begins her own investigation that reveals a murderous, unthinkable conspiracy. Every move Abby makes spawns a vicious backlash...and on a ship anchored in the waters of Boston harbor, the grisly truth lies waiting.