When people in New York City start turning the color blue, the NIH team is called upon to help cure this outbreak. When searching for the cause, a diner holds an important clue.

A group of four teenage girls are suspected of having an STD when they are hospitalized for seizures. However, the NIH team must uncover the true cause of the seizures, and a pair of pants holds a clue.

When the vacationers in a Bahama resort start falling ill, the NIH team is called in to discover the cause of this devastating illness. The only problem is that this disease is not effecting the children. However, when the first child falls ill with the same symptoms, the common link is found, and an illegal drug holds a clue.

The team flies to a small Virgina town to figure out why people are dying from a deadly strain of the flu.

A smallpox outbreak sends the NIH team to Montana. However, is this once thought to have been eradicated disease caused by terrorism, or is it natural?