Carneal's wife dies when his company medical insurance finds a technicality to avoid paying for a liver transplant. He gets fired from his job at the blood bank, mortgages his house and spends his last dollar trying to save her.
Evicted from his house, reduced to possessions he can carry in his car, he is camping when he rises to the defense of a women being brutalized by her boyfriend. Two dead bodies mean fresh organs and Carneal calls a contact he met at the hospital. A team is dispatched to harvest the organs and Carneal gets paid. He refuses the money, but the organ broker blackmails him into harvesting more organs for wealthy clients, or he'll turn Carneal over to the police.
When Carneal was fired he took his laptop with all the clients' blood types, giving him access to thousands of potential donors. The broker orders an organ, he pulls up a list of potentials, and spies on them, determining who is the least worthy to live. Carneal plays God, with a caveat: "I'm not going to kill Mother Teresa to save Paris Hilton."
Carneal begins to pick and choose his victims. The enterprise continues through a series of grisly murders facilitated by an unlicensed surgeon and a cadre of thugs. Things progress until the broker pulls a double cross – he has pre-sold Carneal's kidneys with the rarest of blood types, AB-Negative.