After reporter Marlene Lewis learns she in dying, she hires the guys to find out who infected her with an incurable disease. The guys accept the case and soon learn that Marlene had been working on a story with a man named Don Orley. However, Orley had died of a heart attack before she could discover more. Fortunately, the guys get a lead when Marlene receives a phone message from a man named Jeff Rockwell. Unfortunately, the guys arrive at Rockwell's house only to find that he has apparently hung himself. Searching Rockwell's house, the guys learn that Rockwell worked for the F.D.A. Since Orley, a food engineer working on APS (a food enhancer), would have needed F.D.A. approval, the guys realize the connection between the two dead men. Checking into records on APS, the guys discover that Robert Stockwood is the only member of the AP. research team that has not been killed. Therefore, the guys decide to protect Stockwood. Then, at Orley's funeral, Stockwood disappears after a nearby car explodes. Putting all the facts together, the guys realize that Stockwood is somehow involved in a cover up to hide the deficiencies of APS. The guys further theorize that Orley had been in on it but contacted Marlene when he became scared. From a transmitter that they had previously planted on Stockwood, the guys are able to trace the research scientist. Although they walk into a trap, the guys still manage to gain the upper hand and to capture Stockwood as well as Zeller, the man who actually committed the murders. The episode ends on a sad note for, despite attempts by Murray to find someone who can prepare a cure, Marlene dies.