Quincy, Lee and Danny are all in Lake Tahoe together. Quincy is there for a forensic Pathologist convention and the others for a weekend break. While they are there the guests and staff start coming down with some kind of strange illness. Quincy and a couple of other Forensic Pathologists are called in to help but when some of the patients start dying they still have no clue as to what is killing them. To make things worse the casino owner does not want to admit that anything is wrong, as it will affect his bookings and profits.

The disease continues to spread and the rest of the hotel/casino's guests want to know what is going on. They want to get out of the building but Quincy and his colleagues know that they have to keep the disease, and the guests, contained. If the disease gets out of the hotel it could cause an epidemic that could quickly spread all over the country!

While working late at the lab Quincy and Sam are taken hostage by syndicate chief Vincent DiNardi. He has been poisoned and wants the two medical examiners to find out how the toxin was administered. Once he knows that he can make sure arrangements are completed for his revenge before he dies.

A club near Danny's burns down killing the owner, Lou Chesler. His wife, Elizabeth, is suspected of causing her husband's death, especially by an insurance investigator for the company that held her husbands' life assurance policy. He thinks she has also killed previous men in her life and warns the latest one that he could be next. The latest one is, of course, Quincy.