Reese first catches up with the latest number, Dr. Richard Nelson, when he is being awarded the title of professor emeritus at a lavish dinner banquet. Dr. Nelson is a well respected and renowned cardiac surgeon and researcher, with his credentials suggesting that he is the target. That is indeed the case as Reese and Finch are too late: someone has poisoned Dr. Nelson, probably he ingesting something at that banquet that was slipped into his food or drink. Dr. Nelson first believes that Reese is the culprit, but Reese convinces him that he is only there to help find who did it, even if Reese cannot save him as he finds out the poison is radioactive, which is eating Dr. Nelson's insides and which also means that he will be dead probably within 24 hours. Reese, Finch and Dr. Nelson have to find out what Dr. Nelson ate or drank that was the source of the poison, and wade through the many facets of his life to find the killer. Among the suspects are Dr. Nelson's estranged daughter Molly, or someone tied to the drug trial on which Dr. Nelson sat on the review committee which denied that drug's approval at the eleventh hour. Meanwhile, Simmons threatens Fusco to keep on playing ball with HR or else. Simmons is good on his threat as internal affairs does come knocking on his door regarding the disappearance of Detective Stills. Although he did not kill Stills, he did bury the body. Carter didn't want to hear about Fusco's shady past before, but she has to now to determine if she will help him or let internal find what Simmons wants them to find.