Mac and Det. Flack are called to a seedy motel in Brooklyn when a woman is found shot dead in one of the rooms. Investigators found trace amounts of heroin on her clothes. They soon discover that the victim is Anabel Pino, the wife of a former medical examiner they used to work with, Marty Pino. While on the job, Marty had a horrible gambling problem and devised a plan to steal the organs from the corpses of heroin addicts that passed through his office. He harvested the un-metabolized heroin in their systems so he could then pay-off his debts. Once he was fired from his job, he began to find and kill junkies in order to continue his hideous plan. His wife, trying to pay-off a gambling debt with the harvested heroine, was shot by the loan sharks as revenge. Marty, even after his wife's death, is desperate to find the heroine she had on her when she was killed so he could sell it on his own. When a maid in the motel takes the heroin after finding Anabel's body and tries to sell it to street dealers, Mac and Det. Flack know they must find the maid before Marty does or she could end up like the junkies that have regrettably crossed Marty's path.
Stella enlists the help of Det. Angell in an effort to finally bring down Kolovos and Diakos. She has Det. Angell pose as a rare coins dealer that has position of coins that were stolen from him by his former partners in Greece. Kolovos falls for the trap and leads Stella to Diakos who she finds murdered. While Diakos is now dead and Kolovos is finally going to be brought to justice, Stella feels more that this is an end to one fight and just the beginning of a new one.