Health officials in Albuquerque, New Mexico face an outbreak of a rare and fatal blood disorder. Patients suffer sharp muscular pain, fatigue, fever and rashes. Twenty-one people die from the illness. Five other states report similar cases. The epidemic is spreading. The Center for Disease Control assists federal and state health officials in their hunt for the cause.

In late August of 1999, an infectious disease specialist in Queens, New York reports that she has two elderly patients with neurological disorders. More cases crop up in the following days, several patients die. Initial tests confirm that New York has been hit by an outbreak of the mosquito-borne illness, St. Louis encephalitis. Nearly a month later, exotic birds begin to die at the Bronx Zoo.

A Minnesota mother takes her son to the hospital with signs of food poisoning. While he is being treated, she comes down with the same symptoms. Soon, the Minnesota Department of Health is flooded with calls of food poisoning and launches an investigation. They pinpoint the source to a single restaurant and unwashed and unrefrigerated parsley.

A hospital in Walkerton, Ontario is flooded with patients with the same alarming symptoms. All suffer from fever, nausea and gastrointestinal problems. Health officials suspect water contamination, but the Public Utilities Commission (PUC) reports that the water is safe. The next day, 20 more patients are admitted with the same symptoms.